Propagate exit code from pytest so ci systems can pick up errors

Author: einarf

demosys/management/commands/test.py

@@ -30,4 +30,5 @@ def handle(self, *args, **options):
         if options.get('module'):
             sys.argv.append(options.get('module'))
 
-        pytest.main()
+        exit_code = pytest.main()
+        sys.exit(exit_code)