Check Unit-Test fails

The Unit tests seem to fail frequently. We should check why and solve it.

Description

Expected Behavior

WARNING: DATA RACE                                                                                                                                                                                                                                                                
Read at 0x00c0037a4043 by goroutine 41:                                                                                                                                                                                                                                           
  testing.(*common).logDepth()                                                                                                                                                                                                                                                    
      /usr/lib/go/src/testing/testing.go:774 +0x4e4                                                                                                                                                                                                                               
  testing.(*common).log()                                                                                                                                                                                                                                                         
      /usr/lib/go/src/testing/testing.go:761 +0x6e                                                                                                                                                                                                                                
  testing.(*common).Logf()                                                                                                                                                                                                                                                        
      /usr/lib/go/src/testing/testing.go:807 +0x14                                                                                                                                                                                                                                
  code.fbi.h-da.de/danet/gosdn/nucleus.TestChange_Confirm.func1.1()                                                                                                                                                                                                               
      /home/aps/Code/hda/mpse-gosdn/gosdn/nucleus/change_test.go:203 +0x8f                                                                                                                                                                                                        
  code.fbi.h-da.de/danet/gosdn/nucleus.stateManager.func1()                                                                                                                                                                                                                       
      /home/aps/Code/hda/mpse-gosdn/gosdn/nucleus/change.go:129 +0x338                                                                                                                                                                                                            
                                                                                                                                                                                                                                                                                  
Previous write at 0x00c0037a4043 by goroutine 39:                                                                                                                                                                                                                                 
  testing.tRunner.func1()                                                                                                                                                                                                                                                         
      /usr/lib/go/src/testing/testing.go:1246 +0x584                                                                                                                                                                                                                              
  testing.tRunner()                                                                                                                                                                                                                                                               
      /usr/lib/go/src/testing/testing.go:1265 +0x268                                                                                                                                                                                                                              
  testing.(*T).Run·dwrap·21()                                                                                                                                                                                                                                                     
      /usr/lib/go/src/testing/testing.go:1306 +0x47                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                  
Goroutine 41 (running) created at:                                                                                                                                                                                                                                                
  code.fbi.h-da.de/danet/gosdn/nucleus.stateManager()                                                                                                                                                                                                                             
      /home/aps/Code/hda/mpse-gosdn/gosdn/nucleus/change.go:124 +0x250                                                                                                                                                                                                            
  code.fbi.h-da.de/danet/gosdn/nucleus.TestChange_Confirm.func1()                                                                                                                                                                                                                 
      /home/aps/Code/hda/mpse-gosdn/gosdn/nucleus/change_test.go:207 +0x50a                                                                                                                                                                                                       
  testing.tRunner()                                                                                                                                                                                                                                                               
      /usr/lib/go/src/testing/testing.go:1259 +0x22f                                                                                                                                                                                                                              
  testing.(*T).Run·dwrap·21()                                                                                                                                                                                                                                                     
      /usr/lib/go/src/testing/testing.go:1306 +0x47                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                  
Goroutine 39 (finished) created at:                                                                                                                                                                                                                                               
  testing.(*T).Run()                                                                                                                                                                                                                                                              
      /usr/lib/go/src/testing/testing.go:1306 +0x726                                                                                                                                                                                                                              
  testing.runTests.func1()                                                                                                                                                                                                                                                        
      /usr/lib/go/src/testing/testing.go:1598 +0x99                                                                                                                                                                                                                               
  testing.tRunner()                                                                                                                                                                                                                                                               
      /usr/lib/go/src/testing/testing.go:1259 +0x22f                                                                                                                                                                                                                              
  testing.runTests()                                                                                                                                                                                                                                                              
      /usr/lib/go/src/testing/testing.go:1596 +0x7ca                                                                                                                                                                                                                              
  testing.(*M).Run()                                                                                                                                                                                                                                                              
      /usr/lib/go/src/testing/testing.go:1504 +0x9d1                                                                                                                                                                                                                              
  code.fbi.h-da.de/danet/gosdn/nucleus.TestMain()                                                                                                                                                                                                                                 
      /home/aps/Code/hda/mpse-gosdn/gosdn/nucleus/initialise_test.go:72 +0xbfb                                                                                                                                                                                                    
  main.main()                                                                                                                                                                                                                                                                     
      _testmain.go:145 +0x264 

Actual Behavior

Possible Fix

Steps to Reproduce

Context

Your Environment

• Version used:
• Environment name and version (e.g. go v1.16.3 on FreeBSD 13.0-current):
• Server type and version:
• Operating System and version: