Add test suite and runner to project

[rjaltman]

In the future, we should validate some core functionality based on a series of tests. Since we are using JavaScript for some of this project, we can accomplish parts of that with something like IstanbulJS, but we should probably have some different test run tools for the database itself. I might also recommend Coveralls, which will eventually get us looking into code coverage here.

[ddsnowboard]

I'm not sure we need to test the JavaScript code. We could use some fancy framework to plug into the flask code, or we could just set up something that calls the API over HTTP and makes sure it returns the right thing. I think that might be more practical.

EDIT: I stand by not testing JavaScript, but having something that plugs into Flask might be handy. That might allow us to make database calls without having to worry about messing up the database on our own machines, which is a huge advantage.