Updated email settings for gmail #21

These settings allow the rails mailer to access the google apps smtp
server using perseverance@the-conways.com login information.
Added Booking Mailer #21

Booking mailer is the mailer that will send booking information to
perseverance@the-conways.com on each new guest booking.
On create of guest a new booking email is sent out #21
Merge branch 'build/email' #21