virtual: Move the starter code into the starter module

There is nothing location update specific in the file. Let's move
it into the starter file.

Change-Id: I0cd5705eaf53a14523feacece9446331a53b3e59
diff --git a/src/osmo_gsm_tester/ms_driver.py b/src/osmo_gsm_tester/ms_driver.py
index 329662a..d35f02e 100644
--- a/src/osmo_gsm_tester/ms_driver.py
+++ b/src/osmo_gsm_tester/ms_driver.py
@@ -20,8 +20,8 @@
 from osmo_ms_driver.cdf import cdfs
 from osmo_ms_driver.event_server import EventServer
 from osmo_ms_driver.simple_loop import SimpleLoop
-from osmo_ms_driver.location_update_test import MassUpdateLocationTest, MobileTestStarter
-from osmo_ms_driver.starter import BinaryOptions
+from osmo_ms_driver.location_update_test import MassUpdateLocationTest
+from osmo_ms_driver.starter import BinaryOptions, MobileTestStarter
 
 import os.path
 import shutil