Consider underscores when checking for profanity

[hoverlover]

This PR takes underscores into consideration.

Before:

irb(main):003:0> Obscenity.profane? "shit_head"
=> false

Now:

irb(main):003:0> Obscenity.profane? "shit_head"
=> true

[hoverlover]

Closing PR and re-opening so Travis build will be forced again (it failed due to a build dependency problem).

[hoverlover]

Now that the Travis build is passing, could I please get someone to consider merging this PR so I can go back to using upstream master?

[jslag]

Looks like this repo has been inactive for a year and a half. Not obvious from https://github.com/tjackiw/obscenity/network if there's a clear successor.

[jswencki]

@jslag I've enquired as well, but no reply's. Let me now if you hear anything or maybe you and I can fork and go from there to define one. Would prefer to just get direct commit to here and help, but maybe this isn't doable. Hope all is well with @tjackiw either way.