User and Trip models created
Create users and trips migration
Create models and migrations

-for location_pin, map, photo, post, trip
Merge pull request #1 from Lrmanfre/chore-create-rest-of-models-and-migrations

Chore create rest of models and migrations
Added required validation to migration
Added validations:

- Added presense true validation to most belongs_to
- Added email and password validation
- NOTE: Photo/Posts can only be created through LocationPin association and REQUIRE a trip instance in order to be created
Added required true validation