Get Travis running, update specs to be green.

Key changes:

1. Update the specs so they pass across Rubies
2. Add a .travis.yml
3. Loosen the gem restrictions in the gemspec
4. Add files to .gitignore

After this PR is merged a committer will need to activate Travis for this repository at http://travis-ci.org.  The specs should all run green.  You can see a Travis run here - https://travis-ci.org/petergoldstein/rollout/builds/16848843