Replace voluptuous with JSONSchema to validate change_nova_service_state

Now in watcher,both JSONSchema and voluptuous are used to validate
JSON payloads. We want to remove voluptuous and Use
JSONSchema as our only JSON validation tool to keep consistence
and also to make it easier to expose the validation schema
through our API in future work.

In this patch, we replace voluptuous with JSONSchema to validate
the change_nova_service_state action in watcher applier.

Partially Implements: blueprint jsonschema-validation

Change-Id: I09a03fff96d9555024a74ba255c6951affc39de8

watcher/tests/applier/actions/test_change_nova_service_state.py

@@ -15,8 +15,8 @@
 
 from __future__ import unicode_literals
 
+import jsonschema
 import mock
-import voluptuous
 
 from watcher.applier.actions import base as baction
 from watcher.applier.actions import change_nova_service_state
@@ -73,33 +73,20 @@ class TestChangeNovaServiceState(base.TestCase):
         self.action.input_parameters = {
             baction.BaseAction.RESOURCE_ID: "compute-1",
             self.action.STATE: 'error'}
-        exc = self.assertRaises(
-            voluptuous.Invalid, self.action.validate_parameters)
-        self.assertEqual(
-            [(['state'], voluptuous.ScalarInvalid)],
-            [([str(p) for p in e.path], type(e)) for e in exc.errors])
+        self.assertRaises(jsonschema.ValidationError,
+                          self.action.validate_parameters)
 
     def test_parameters_resource_id_empty(self):
         self.action.input_parameters = {
             self.action.STATE: element.ServiceState.ENABLED.value,
         }
-        exc = self.assertRaises(
-            voluptuous.Invalid, self.action.validate_parameters)
-        self.assertEqual(
-            [(['resource_id'], voluptuous.RequiredFieldInvalid)],
-            [([str(p) for p in e.path], type(e)) for e in exc.errors])
+        self.assertRaises(jsonschema.ValidationError,
+                          self.action.validate_parameters)
 
     def test_parameters_applies_add_extra(self):
         self.action.input_parameters = {"extra": "failed"}
-        exc = self.assertRaises(
-            voluptuous.Invalid, self.action.validate_parameters)
-        self.assertEqual(
-            sorted([(['resource_id'], voluptuous.RequiredFieldInvalid),
-                    (['state'], voluptuous.RequiredFieldInvalid),
-                    (['extra'], voluptuous.Invalid)],
-                   key=lambda x: str(x[0])),
-            sorted([([str(p) for p in e.path], type(e)) for e in exc.errors],
-                   key=lambda x: str(x[0])))
+        self.assertRaises(jsonschema.ValidationError,
+                          self.action.validate_parameters)
 
     def test_change_service_state_pre_condition(self):
         try: