Fixed #28626 -- Dropped support for PostgreSQL 9.3.

Thanks Simon Charette for the introspection changes.

tests/postgres_tests/__init__.py

@@ -7,16 +7,6 @@ from django.db.backends.signals import connection_created
 from django.test import TestCase, modify_settings
 
 
-def skipUnlessPG94(test):
-    try:
-        PG_VERSION = connection.pg_version
-    except AttributeError:
-        PG_VERSION = 0
-    if PG_VERSION < 90400:
-        return unittest.skip('PostgreSQL ≥ 9.4 required')(test)
-    return test
-
-
 @unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific tests")
 class PostgreSQLTestCase(TestCase):
     @classmethod