should run in travis ci

## motivation

I am about to start pushing changes to implement Xcode 6 + Yosemite compatibility.  I need tests to ensure that I don't break backward compatibility.  I would like these tests be run against the ruby versions we support.  Travis CI is good fit testing backward compatibility because it is running Xcode 5.1 + Mavericks.

This PR wires up run_loop to travis-ci.  The current test is simple; call $ bundle install --deployment.

My plan is to implement the run_loop tests in rspec.

This PR also adds Gemfile.lock to the git index.

## todo

- [ ] @krukow needs review