Add a Continuous Integration Tool for Build Status + PR Checks

Intend to use [TravisCI](https://travis-ci.org/) for this. This involves adding a `.travis.yml` and setting up Travis through the website.

### Helpful stuff
- Core-v4's [`.travis.yml`](https://github.com/SCE-Development/Core-v4/blob/dev/.travis.yml)
- PR adding the file in Core-v4 [#117](https://github.com/SCE-Development/Core-v4/pull/117)
