Travis CI / Repoman for this overlay

Travis CI is a continuous integration solution with tight Github integration that provides free services to all open source projects on Github.

I have put together a `.travis.yml` file for this repository to automatically run Gentoo's repoman on every commit and pull request. The reason for running tests like these is to ensure a high level of quality is achieved and maintained within the repository in accordance with the suggested guidelines for the entire Gentoo ecosystem.

If you are interested in this pull request, it will be necessary to enable this repository with a Travis CI hook to automatically run this on all future builds.

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Given in it's present form this overlay did not meet the standards outlined by repoman, I have performed the necessary changes required to make it pass these tests.

This included:
* Inclusion of the Sublime license agreement in text.
* Cleaning up tabs and spaces.
* Adding an extra metadata.xml file