Remove failing test

Why were we comparing two different string and trying to assert
their equality?  It would never pass, right?
Remove ebin/twilio.app (rebar auto-generates it)
Update .gitignore

Ignore ebin completely as well as .eunit
Use mochiweb master instead of a specific version

Mochiweb master is better than a much older version, and
master works on R16B+ instead of being tied to R15B and lower
like previous versions. (yes, that's only if you're actually
starting and using mochiweb, but we can't have conflicing
versions if we're using this twilio module within a larger
app on R16B that also uses mochiweb.)