Updated Adafruit GPS library nd cleaned up motion class

Some updates to the GPS class within the Motion module.  

Specifically, to support WAAS for better location resolution: 

https://github.com/adafruit/Adafruit-GPS-Library/commit/7a3956fbac33fdebdc71fdab7c8e0e0b7e964079#diff-ad0c0bd27aa3b33b266fdac1947162cdR58