OTWO-3248: Convert Ohloh SCM into a gem

The function url_regex needs to match "@" in urls to support Ohloh's
tests. Since rvm gem paths will have gemset@ruby pattern, @ can be a
part of url for repositories inside this library's test folder.

The `@` is needed to match Ohloh tests?  If it is needed ONLY for Ohloh tests, then it doesn't belong in production code.