Remove unneeded code from observer drive target slewing example

Author: jkonish

getting_started/observer/driving/drive_target_slewing.py

@@ -3,14 +3,10 @@
 import time
 sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '../../../')))
 
-import asyncio
 from sphero_sdk import SpheroRvrObserver
-from sphero_sdk import SerialAsyncDal
 from sphero_sdk import LinearVelocitySlewMethodsEnum
 
 
-loop = asyncio.get_event_loop()
-
 rvr = SpheroRvrObserver()
 
 # Flag for tracking position move completion