tests the user-password-update for Keystone V2 API

This patch adds JSON/XML client and test for below Keystone V2 API :
1. user-password-update

Change-Id: Ifa1b3e005c82f09b8ba63b6cd8a6671892f5006f
diff --git a/tempest/api/identity/admin/test_users.py b/tempest/api/identity/admin/test_users.py
index a4e6c17..e2c1066 100644
--- a/tempest/api/identity/admin/test_users.py
+++ b/tempest/api/identity/admin/test_users.py
@@ -206,6 +206,25 @@
                          "Failed to find user %s in fetched list" %
                          ', '.join(m_user for m_user in missing_users))
 
+    @test.attr(type='smoke')
+    def test_update_user_password(self):
+        # Test case to check if updating of user password is successful.
+        self.data.setup_test_user()
+        # Updating the user with new password
+        new_pass = data_utils.rand_name('pass-')
+        resp, update_user = self.client.update_user_password(
+            self.data.user['id'], new_pass)
+        # Assert response body of update user.
+        self.assertEqual(200, resp.status)
+        self.assertEqual(update_user['id'], self.data.user['id'])
+
+        # Validate the updated password
+        # Get a token
+        resp, body = self.token_client.auth(self.data.test_user, new_pass,
+                                            self.data.test_tenant)
+        self.assertEqual('200', resp['status'])
+        self.assertTrue('id' in body['token'])
+
 
 class UsersTestXML(UsersTestJSON):
     _interface = 'xml'
diff --git a/tempest/services/identity/json/identity_client.py b/tempest/services/identity/json/identity_client.py
index 55239f7..479a289 100644
--- a/tempest/services/identity/json/identity_client.py
+++ b/tempest/services/identity/json/identity_client.py
@@ -227,6 +227,16 @@
         url = '/OS-KSADM/services/%s' % service_id
         return self.delete(url)
 
+    def update_user_password(self, user_id, new_pass):
+        """Update User Password."""
+        put_body = {
+            'password': new_pass,
+            'id': user_id
+        }
+        put_body = json.dumps({'user': put_body})
+        resp, body = self.put('users/%s/OS-KSADM/password' % user_id, put_body)
+        return resp, self._parse_resp(body)
+
 
 class TokenClientJSON(IdentityClientJSON):
 
diff --git a/tempest/services/identity/xml/identity_client.py b/tempest/services/identity/xml/identity_client.py
index c48bc90..b213c1a 100644
--- a/tempest/services/identity/xml/identity_client.py
+++ b/tempest/services/identity/xml/identity_client.py
@@ -118,6 +118,15 @@
                                str(xml.Document(create_service)))
         return resp, self._parse_resp(body)
 
+    def update_user_password(self, user_id, new_pass):
+        """Update User Password."""
+        put_body = xml.Element("user",
+                               id=user_id,
+                               password=new_pass)
+        resp, body = self.put('users/%s/OS-KSADM/password' % user_id,
+                              str(xml.Document(put_body)))
+        return resp, self._parse_resp(body)
+
 
 class TokenClientXML(identity_client.TokenClientJSON):
     TYPE = "xml"