Add pony and mailcatcher for emailing, plus email config
Load pony gem in app.rb
Add user mailer observer, which sends mail to two users

Currently not hooked up to send the mail.
Add spec test for the working case of two users

Also rename spec to reflect class name
Allow observers to be added to Code and send users_assigned message

Also move private methods to the bottom of the class under the private
keyword.
Fix the nil code error in the app spec

Plus correct the block passed to should_receive for the user_mailer
spec.
Eliminate gender from mail body
Merge pull request #40 from joonty/mail-fun

Email users on successful pairing, close ##37