add username to people and make unique to account
delegate username to user
add username field to edit user settings
Add usernames to accounts #391
Add capybara for integration tests #407
add signup feature spec
add username to new account / signup form
Make accepting an invitation have the same layout / look as the new
signup #408

  - also added username field to form
remove pry debugger
Merge pull request #184 from jess/username

add username, setup capybara, add some integration specs, redesign invitation signup page