[autotest] Drop {Base,Site}DroneUtility

'cause we're all one.

BUG=chromium:718181
TEST=None

Change-Id: I0b5707e4e30574e14be1cdc3874882e001062823
Reviewed-on: https://chromium-review.googlesource.com/524268
Commit-Ready: Prathmesh Prabhu <pprabhu@chromium.org>
Tested-by: Prathmesh Prabhu <pprabhu@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Reviewed-by: Xixuan Wu <xixuan@chromium.org>
diff --git a/scheduler/drone_utility.py b/scheduler/drone_utility.py
index e832932..6d78c5a 100755
--- a/scheduler/drone_utility.py
+++ b/scheduler/drone_utility.py
@@ -79,7 +79,7 @@
     return _MethodCall(method, args, kwargs)
 
 
-class BaseDroneUtility(object):
+class DroneUtility(object):
     """
     This class executes actual OS calls on the drone machine.
 
@@ -601,13 +601,6 @@
     return parser.parse_args(args)
 
 
-SiteDroneUtility = BaseDroneUtility
-
-
-class DroneUtility(SiteDroneUtility):
-    pass
-
-
 def return_data(data):
     print pickle.dumps(data)