This was yielding incorrect bearing calculations (east and west were
treated as the same direction).

Only worked with MySQL.

Was preventing other test from running.

Improve comments, make code style consistent with rest of Geocoder, and
remove options (keep it dead simple).

Adds methods for calculating the bearing between two points and for converting that bearing into a compass point, e.g. North or South West. If you want fewer or additional compass points (e.g. South By South West, or just NESW) provide a second parameter containing your array of points, e.g. Geocoder::Calculations::compass_point(90,['north','east','south','west'])

Add option "bearing". When set to :line or :spherical it returns the bearing of the record from the search point, i.e. if the record is due north you'll see 0.0 returned. :line is a straight line, :spherical is the shortest path where the bearing between two points varies with distance to take into account curvature of the planet.

...for array methods mistakenly called on a Result object. This is no
longer likely to be a problem now that Geocoder.search returns an array.

...for Result instance methods mistakenly called on an array.

After further consideration, multiple results should be the default
behavior for this method. Some services only return one result (eg: any
IP-based service) but a great feature of advanced services like Yahoo
and Google is that they return an array of choices when doing a vague
search like "100 Main St" with no city, region, or country specified.

Google results don't return a 'city', so we have to look at several
fields in descending order of preference.

Now that we also support an API key for Google it makes sense for this to
be generic.

Replaces read_coordinates (private) and fixes bug in geographic center
computation (reported by github.com/jonbuda).

This allows us to add a method for expiring cache keys and generally
gives us more control over the cache interface.

Just set Geocoder::Configuration.cache to any key/value store that
implements #[], #[]=, and #keys. You can also set
Geocoder::Configuration.cache_prefix to use a custom prefix for keys.