Use 'localhost' interface, avoid weird auth error in test_common

Author: A. Jesse Jiryu Davis

test/test_common.py

@@ -23,7 +23,7 @@
 from pymongo.errors import ConfigurationError, OperationFailure
 
 
-host = os.environ.get("DB_IP", socket.gethostname())
+host = os.environ.get("DB_IP", 'localhost')
 port = int(os.environ.get("DB_PORT", 27017))
 pair = '%s:%d' % (host, port)