Set up CI

CI needs to do a ton of things eventually (see below). For now, set up a CI instance for this repository so that the things below (each with their own issue) can be implemented eventually.

- Testing
  - Metadata checker
  - Dependency tree logic
  - Splle c hkjser 
  - Pep8 checker
  - LaTeX build checker
- Deployment
  - Build jekyll website
  - Build d3.js dependency graph
