clean up go mods

go.mod

@@ -3,8 +3,8 @@ module code.fbi.h-da.de/cocsn/yang-models
 go 1.15
 
 require (
-	code.fbi.h-da.de/cocsn/gosdn v0.0.1 // indirect
+	github.com/golang/protobuf v1.4.2
 	github.com/openconfig/goyang v0.2.2
 	github.com/openconfig/ygot v0.10.0
-	github.com/sirupsen/logrus v1.8.0 // indirect
+	google.golang.org/protobuf v1.23.0
 )