Alert user if map cannot be shown due to no Play services
Check for Internet connectivity.

Check before querying API, and quit app if no connection found.
Use URI builder to build Civic API query string
Update README; tidying
Perform distance calculation in geocode async task
Bump minimum SDK version to 16.

This will allow us to use otherwise deprecated call in Maps fragment, causing Travis to fail.
Added geocoding error handling
Linting
Set min SDK back to 15 and check version number in ViewTreeObserverCall.

Also more linting and linter warning suppression.
Merge pull request #22 from flibbertigibbet/feature/make-robust

Feature/make robust