def post(self, name=None, author=None):
"""
' PURPOSE
' Given a trip name and author identifier, create
' a new trip. Returns the identifier of the new trip.
' PARAMETERS
' <str name>
' <str author> identifier
' RETURNS
' dict( id )
' id -> the identifier of the created trip
"""
author_key = UserModel.key_from_id(author)
trip = TripModel(name=name, author=author_key).save()
return { 'id': trip.key.id }
