#169 Unit test for CurrentUserStore.

Will probably need to test more extensively, but it ensures that getCurrentUser is returning the correct user.
- This isn't python; don't forget semicolons! (Next line, too). Javascript lets it slide in certain cases with automatic semicolon insertion, but it doesn't make for consistently-styled code.
- Our convention will be to tightly hug object literals with the braces, e.g. `{user_type: 1}`, similarly to python dictionaries.