Start adding more tests

I started the process of adding more tests to the project. All of them are very basic at this point. I am using [shoulda-matchers](https://github.com/thoughtbot/shoulda-matchers) to do all the basic validation and relationship testings. It's nice and clean that way instead of writing longer specs. Not sure if you have a preference on those sorts of things.

I had to update a bunch of settings to get everything to work properly for testing. Most notably, I added a `.rspec` file, and updated the rspec config to work with `Capybara`. I also had to do some stuff to the `Gemfile` to resolve some errors. The `better_errors` gem had to be moved to the `development` group instead of the `development, test` group. There was an error/warning when I ran `rspec` which was caused by a `specific` version of `rack` so I locked it to the most recent version that didn't cause the warning. When upgrading to Rails 4 in the future, it would be best to remove the lock on `rack`.

Lastly, `guard` does not work for me. There is a dependency conflict that I can't figure out how to resolve (spent a fair amount of time trying to fix it). I will open up an issue to describe it more in detail.