Issue #192 - Add regId and deviceType in the session model
Fix a typo in the offer model documentation
Add PendingInvitation and InvitationMessage model
Add missing lines to models
Add migration for session , pendingInvitation and invitationMessage
Test the models
Merge pull request #199 from ndomar/Database-Models

Database_Add migration for session , pendingInvitation and invitationMessage
Issue #163 - Add email field and making inviteeId nullable
Merge pull request #200 from ndomar/Database-Models

Database_Add emain in Pending invitation and make inviteeId nullable
Add Deleted column
Merge pull request #204 from ndomar/Database-Models

Database_Add Deleted column
before pull
Issue #179 resolving conflict
Issue 179 - Backend to get/set notification status