Add importing modules instead of classes

This patch removes import of classes and replaces them with import of modules.

Change-Id: Id2502cf96ac7227cf1036cd54a74f3d7acd83479
Closes-Bug: #1594434

watcher/decision_engine/messaging/events.py

@@ -17,10 +17,10 @@
 # limitations under the License.
 #
 
-from enum import Enum
+import enum
 
 
-class Events(Enum):
+class Events(enum.Enum):
     ALL = '*',
     ACTION_PLAN = "action_plan"
     TRIGGER_AUDIT = "trigger_audit"