Delete unused class Service

The base class 'Service' in tempest/__init__ seems not to be used any
longer due to various reworks in the code.

Change-Id: I491293e4adf8239f1426baa5432aad4f67001ac0

tempest/services/__init__.py

@@ -1,37 +0,0 @@
-# Copyright 2012 OpenStack Foundation
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-"""
-Base Service class, which acts as a descriptor for an OpenStack service
-in the test environment
-"""
-
-
-class Service(object):
-
-    def __init__(self, config):
-        """
-        Initializes the service.
-
-        :param config: `tempest.config.Config` object
-        """
-        self.config = config
-
-    def get_client(self):
-        """
-        Returns a client object that may be used to query
-        the service API.
-        """
-        raise NotImplementedError