[FEATURE] Create PgModel instead of using a mixin
[TEST] Finish preparing test for belongsTo association
[FEATURE] Set up belongsTo querying
[FEATURE] 'hasMany' allows model to query with ;
[TESTS] Write test for has many through relation
[TESTS] Write test for has many through relation
[FEATURE] Add hasManyThrough association
Merge pull request #2 from keremdaldal/feature/pg-associations

[FEATURE] Add postgreSQL associations