Fix H404/405 violations for scenario tests

There is a lot of H404/405 violations in Tempest now, and that leads
difficult to migrate the code to tempest-lib or the other projects'
repos. This patch fixes these violations for scenario tests.

Change-Id: Ia2b3cdbd0da49eeb16742c1eed05ea56ca41a8f7
diff --git a/tempest/scenario/test_snapshot_pattern.py b/tempest/scenario/test_snapshot_pattern.py
index 5ac3a7e..f56a5fb 100644
--- a/tempest/scenario/test_snapshot_pattern.py
+++ b/tempest/scenario/test_snapshot_pattern.py
@@ -26,8 +26,8 @@
 
 
 class TestSnapshotPattern(manager.ScenarioTest):
-    """
-    This test is for snapshotting an instance and booting with it.
+    """This test is for snapshotting an instance and booting with it.
+
     The following is the scenario outline:
      * boot an instance and create a timestamp file in it
      * snapshot the instance