GitHub User: emeryamiller
For those getting a 401 error - OAuth::Unauthorized I found the following two things could generate this:
1. When setting up the twitter account you must specify the return url (use 127.0.0.1 instead of localhost as localhost won't validate as a proper url). If you don't, twitter will set your account as a client call type, not a browser call, and somehow this ends in a 401 error.
2. A mistake in pasting in the two provider keys that twitter provided.