adding the invitation email link to the party page
Create send party invitations form
Install RestClient and set up Mailgun
Merge branch 'master' of github.com:Harrisam/hen_party into hen_token_emails

Conflicts:
	app/helpers/application_helper.rb
	app/views/parties/show.html.erb
Add PartyInvitation mailer to send invite emails with token links to join
Merge branch 'master' of github.com:Harrisam/hen_party into hen_token_emails