Update models.md
Adds flow to add users to event during Event.create call
Merge pull request #12 from techiev2/events

Adds flow to add users to event during Event.create call
Updates event members key in request payload
Merge pull request #14 from techiev2/events

Updates event members key in request payload
Adds device sent id fields for User, Event, Task models
Merge branch 'master' into users
Merge branch 'users' of github.com:techiev2/HaywireAPI into users