Better testing / Travis CI

[jameslzhu]

Testing is pretty much non-existent right now.

The current Travis-CI, configured with .travis.yml, does three things on a freshly installed Ubuntu 16.04 OS:

• Install dependencies, with pipenv
• Run SQL migrations (python manage.py migrate)
• Run checks (python manage.py check)

And that's it. No tests on if anything actually works, no tests if urls hit the right pages, no checks if methods work, or really anything.

A good first start on this will be route tests: checking if a GET request to a specific url returns the right page. Beyond this we can check for db functionality on POST / GET requests, etc.

Relevant docs pages:

• Django reference on testing
• Django tutorial on testing
• Testing tools

[bri25yu]

Closed by #447 and #443