Preserve consistency in module namings

We rename several modules in the system (mostly in unit tests) so that their
namings become consistent throughout the code.

"Consistency" means here following certain rules like "name all deploy engine
and server provider modules without _engine.py and _provider.py suffixes" or
"name all unit tests like test_<tested_module>.py".

We also add a couple of new folders in unit tests so that the unit tests
structure strictly resembles that of tested modules.

Blueprint unit-tests-refactoring

Change-Id: Ia7b6afce0d1e20b969b56301e0c9ad0f94cc60e4

tests/deploy/engines/test_dummy.py

@@ -18,7 +18,7 @@
 import jsonschema
 
 from rally import deploy
-from rally.deploy.engines import dummy_engine
+from rally.deploy.engines import dummy
 from rally import test
 
 
@@ -41,28 +41,28 @@ class TestDummyDeployEngine(test.TestCase):
         super(TestDummyDeployEngine, self).setUp()
 
     def test_dummy_egnine_init(self):
-        dummy_engine.DummyEngine(self.deployment)
+        dummy.DummyEngine(self.deployment)
 
     def test_dummy_engine_deploy(self):
-        engine = dummy_engine.DummyEngine(self.deployment)
+        engine = dummy.DummyEngine(self.deployment)
         endpoint = engine.deploy()
         self.assertEqual(endpoint, self.deployment['config']['cloud_config'])
 
     def test_dummy_engine_cleanup(self):
-        dummy_engine.DummyEngine(self.deployment).cleanup()
+        dummy.DummyEngine(self.deployment).cleanup()
 
     def test_dummy_engine_is_in_factory(self):
         name = self.deployment['config']['name']
         engine = deploy.EngineFactory.get_engine(name,
                                                  self.deployment)
-        self.assertIsInstance(engine, dummy_engine.DummyEngine)
+        self.assertIsInstance(engine, dummy.DummyEngine)
 
     def test_init_invalid_config(self):
         self.deployment['config']['cloud_config']['identity'] = 42
         self.assertRaises(jsonschema.ValidationError,
-                          dummy_engine.DummyEngine, self.deployment)
+                          dummy.DummyEngine, self.deployment)
 
     def test_deploy(self):
-        engine = dummy_engine.DummyEngine(self.deployment)
+        engine = dummy.DummyEngine(self.deployment)
         self.assertEqual(self.deployment['config']['cloud_config'],
                          engine.deploy())