Travis-CI integration

This pull request adds Travis-CI integration to the repository. On each push to each branch, Travis-CI will automatically run tests. Pull requests will now display the status of the build, and the badge in the README will display the status of the build for master.

This will also send a message to the frenetic IRC channel every time a build fails, and when the build goes form failing to passing. (However it won't send a message on consecutive passes.)