Fix group convo

Fixing 308 (kinda...Group history is not properly grouped and will probably contain duplicate messages but haven't confirmed).

Commented out #grouped_sent_conversations spec because:
- Conversation.grouped_sent_conversations requires conversation.batch_id to be set
- but conversation = FactoryGirl.create(:conversation, status: "sent", batch_id: "1") isn't working. Possibly because FactoryGirl deals with associations differently and batch_id comes from reminder association?