Significant rework - fixed bugs, spelling of acquire method, made into gem, added CI tests etc

Thanks for your library - I had to investigate it because I was having problems in a project I used it with, so I got stuck in and  significantly reworked it into a gem,
with tests (the old aquire! overwrites the lock file without checking if the lock is active),
changed methods with ! to throw exception on fail,
added methods that return status,
allow blocks to be passed (releases lock after block),
fixed spelling (acquire not aquire - yeah for spell checkers),
added travis CI testing and link to same,
added filename attribute.

Alternatively if you are no longer maintaining the library, do you want to add a comment in README pointing to my version?