Response#set_association
Bug fixes, passing tests.
Add validations for ProjectUpdate and Reply.
ReplyMailer and ProjectMailer tests
Replies Digest - and test
ReplyMailer#projects_update_reminder
Prevent duplicate responses for a reply or project update.
Add link to updates page in emails asking for reply.
Only show replies with content.
WIP - Add Reply form to ProjectUpdates#show
Web UI for adding replies