Capture User Geo

Summary
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Closes #4

Adds `GoogleLocationServiceActivity` to capture user Geo on an interval.
   + This class should be used for any activity that  captures user geo
   + Verified that geo data is actually saved to user's parse data
   + Subclasses RequestMapActivity to test

 My next steps will be to broadcast this data to a channel, which can be consumed by other users
Merge pull request #27 from steffanc/4-user-geo

Capture User Geo