Updated test coverage stats from coveralls.
Wrote unit tests for Apartment.
Wrote Property unit tests.
Updated parking_types and apartments acceptance/integration tests to account for users submitting invalid input.
Removed unused attributes from Property.
 Wrote unit tests for ParkingType, updated validations to constrain accepted values for category and on_site, adjusted acceptance test accordingly.
Wrote unit tests to constrain amenity_set attributes to only true/false.
Updated parking_type unit test to allow for nil values.
Returned parking_type acceptance test to its original state (it was fine, the validations needed to be updated to allow nil values in unused forms).