Emily's rest controller

Let's be real, it's an address book. anyways, @ndelage @dukegreene @rmw, any feedback would be appreciated. Thanks!
If you want to avoid the repetitive `if address` checks, just instantiate a new (empty) address object in your controller:

```ruby
get "/contacts/:contact_id/addresses/new" do
  @contact = Contact.find(params[:contact_id])
  @address = Address.new
end
```