Suggestion (update included): include file name with warnings

I was getting a security warning like this:

Session secret should not be included in version control near line 7 

-- which begged the question: in which file? Usually it would be config/initializers/secret_token.rb, of course, but I am a sporadic Rails developer, and don't always remember where everything is. I think it would help a lot to have the file named in the warning.