Allow running with postgres

runtests.py

@@ -4,11 +4,18 @@
 
 from django.conf import settings
 
+if len(sys.argv) > 1 and 'postgres' in sys.argv:
+    sys.argv.remove('postgres')
+    db_engine = 'postgresql_psycopg2'
+    db_name = 'test_main'
+else:
+    db_engine = 'sqlite3'
+    db_name = ''
+
 if not settings.configured:
     settings.configure(
-        DATABASE_ENGINE = 'sqlite3',
-        # DATABASE_ENGINE = 'postgresql_psycopg2',
-        # DATABASE_NAME = 'test_main',
+        DATABASE_ENGINE = db_engine,
+        DATABASE_NAME = db_name,
         INSTALLED_APPS = [
             'django.contrib.contenttypes',
             'generic_aggregation.generic_aggregation_tests',