Remove trove as default value for Service Name

* This causes service catalog lookup issues when the Catalog
  contains service_type = database, but service_name = somethine_else

fixes bug 1228372

Change-Id: I1f7eebb06d7f57c0ecc95d8c05104f43e803c406

troveclient/client.py

@@ -296,7 +296,7 @@ class Dbaas(object):
     """
 
     def __init__(self, username, api_key, tenant=None, auth_url=None,
-                 service_type='database', service_name='trove',
+                 service_type='database', service_name=None,
                  service_url=None, insecure=False, auth_strategy='keystone',
                  region_name=None, client_cls=TroveHTTPClient):
         from troveclient.versions import Versions

troveclient/common.py

@@ -92,7 +92,7 @@ class CliOptions(object):
         'auth_url': None,
         'auth_type': 'keystone',
         'service_type': 'database',
-        'service_name': 'trove',
+        'service_name': '',
         'region': 'RegionOne',
         'service_url': None,
         'insecure': False,

troveclient/tests/test_common.py

@@ -82,7 +82,6 @@ class CliOptionsTest(TestCase):
         self.assertEqual(None, co.auth_url)
         self.assertEqual('keystone', co.auth_type)
         self.assertEqual('database', co.service_type)
-        self.assertEqual('trove', co.service_name)
         self.assertEqual('RegionOne', co.region)
         self.assertEqual(None, co.service_url)
         self.assertFalse(co.insecure)