WIP - Associate shop with user

Need to merge in index_test branch
Right now, `user` is nil (you should be getting a `undefined local variable or method `user'` error when you run your specs).  That's because you've commented out your `user` variable assignment line.  

There are two ways you can create a user and associated coffee shop:
```ruby
# create user, then create a shop associated w/ that user
user = FactoryGirl.create(:user)
shop = FactoryGirl.create(:shop, user: user)

# create a shop, then assign that shop's user (created via the shop factory's association) to the user variable
shop = FactoryGirl.create(:shop)
user = shop.user
```