tempest: fix some future flake8 issue

Change-Id: I37f2aa3e125dd38dae5ae6bc17e88472a8dea903
diff --git a/ceilometer/tests/tempest/scenario/test_telemetry_integration.py b/ceilometer/tests/tempest/scenario/test_telemetry_integration.py
index e173107..aa4703a 100644
--- a/ceilometer/tests/tempest/scenario/test_telemetry_integration.py
+++ b/ceilometer/tests/tempest/scenario/test_telemetry_integration.py
@@ -95,7 +95,7 @@
             "NEUTRON_NETWORK": networks[0].get('id'),
         })
 
-        with file(os.path.join(TEST_DIR, filename)) as f:
+        with open(os.path.join(TEST_DIR, filename)) as f:
             test_suite = suitemaker.test_suite_from_dict(
                 loader=unittest.defaultTestLoader,
                 test_base_name="gabbi",
@@ -132,6 +132,7 @@
         test.__name__ = name
     return test
 
+
 # Create one scenario per yaml file
 for filename in os.listdir(TEST_DIR):
     if not filename.endswith('.yaml'):