Improve usability and better output formatting for gosndc

Description

Related Issue

#188 (closed)

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

controller/api/initialise_test.go

@@ -90,7 +90,7 @@ func bootstrapUnitTest() {
 	mockPnd.On("PendingChanges").Return([]uuid.UUID{changeUUID})
 	mockPnd.On("CommittedChanges").Return([]uuid.UUID{changeUUID})
 	mockPnd.On("GetChange", mock.Anything).Return(mockChange, nil)
-	mockPnd.On("AddDevice", mock.Anything, mock.Anything, mock.Anything).Return(nil)
+	mockPnd.On("AddDevice", mock.Anything, mock.Anything, mock.Anything).Return(nil, nil)
 	mockPnd.On("GetDevice", mock.Anything).Return(&nucleus.CommonDevice{
 		UUID:  deviceUUID,
 		Model: &openconfig.Device{},