updates smarty streets api key requirements

Document google free API requiring https

I stumbled here, ended up finding the answer in the [issues](https://github.com/alexreisner/geocoder/issues/698). Would be great to document this in the main readme.

Update to Bing on README on usage.

See: https://github.com/alexreisner/geocoder/issues/703

Update so opencagedata will return coordinates.

In the current opencagedata api, latitude and longitude are stored under geometry: {lat: ..., lng: ...}

Allow language to be set in geocoded_by as proc

Refactor SQL statement to prevent table join

Smartystreets is no longer free for non-profits

This should have been part of commit 47e11a41.

Get rid of extraneous "q=" in request query string.

Opencagedata: additional tests

add alternate attributes options for near_scope_options

No longer documented. Removing to avoid confusion.
See: http://notes.ericjiang.com/posts/741

Add opencagedata geocoder, incl tests and fixtures

Add support for Pointp.in ip geolocation

Allow lookup service to fully opt-out of https