Use API V2 driver as default db driver

Change-Id: I83000f8bf39eed41d067ed663de9f459439eca9a

freezer_api/api/v2/jobs.py

@@ -174,7 +174,7 @@ class JobsEvent(resource.BaseResource):
         doc = self.json_body(req)
 
         try:
-            event, params = next(doc.items())
+            event, params = next(iter(doc.items()))
         except Exception:
             raise freezer_api_exc.BadDataFormat("Bad event request format")
 

freezer_api/storage/driver.py

@@ -34,7 +34,7 @@ _OPTS = [
                     "the database."
                ),
     cfg.StrOpt('driver',
-               default='freezer_api.storage.elastic.ElasticSearchEngine',
+               default='freezer_api.storage.elasticv2.ElasticSearchEngineV2',
                help="Database driver to be used."
                )
 ]