adds email functionality
improves trip show page layout
adds join event button with logic
users can join trips
fixes email, emails now come from snowcial, not user.
users now get nice messages to let them know their emails have been sent!
updates local master
resolves merge conflicts, adds resort relationships to seed data, changes trip/resort model relationships
resolves merge conflicts, adds resort relationships to seed data, changes trip/resort model relationships
resolves instas issue