add postgres Fact model, update views, tests

* awx.main.models Fact added
* view host fact and timeline updated to use new Postgres Fact model instead of Mongo
* Removed license set start Mongo logic
* added View tests
* added Model tests
* Removed mongo fact unit tests
* point at modified jsonbfield that supports sqlite storage driver
* postgresify fact cache receiver
* test OPTIONS endpoint
* Note: single fact view not implemented yet.

awx/main/migrations/0003_auto_20160209_1615.py

@@ -17,8 +17,6 @@ class Migration(migrations.Migration):
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
                 ('timestamp', models.DateTimeField(default=None, editable=False)),
-                ('created', models.DateTimeField(auto_now_add=True)),
-                ('modified', models.DateTimeField(auto_now=True)),
                 ('module', models.CharField(max_length=128)),
                 ('facts', jsonbfield.fields.JSONField(default={}, blank=True)),
                 ('host', models.ForeignKey(related_name='facts', to='main.Host')),