added RemoveReferenceSample BUT produces the following error when trying...

... to run the test:

Test 'M:RemoveReferenceSample.Sample.Run' failed: Could not load type 'RemoveReference.RemoveReferenceAttribute' from assembly 'nunit.framework, Version=2.6.2.12296, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77'.

Any advice?
Thank you.