Add /retreat page.
Started building /retreat page.
Added form and payment.

Forgot how to use Rails lol. Added form and stripe payment. Added some details and WIP email confirmations.
Finished most of the form. Speaker profiles still WIP.
Removed speaker profiles for now.
Added auto-email for retreat payments.
Fixed potential failure.
Prob shouldn't have done that, yeah?
Merge pull request #181 from tmcyf/retreat

Retreat feature