Install Geocoder for Google API access, simplify presenter logic
whitespace
Add tests for RetailerPresenter
Clean up and documentation for classes and tests
Move Yelp logic out of Retailer, add tests, RetailerPresenter updates

* Update RetailerPresenter so that setting state is more clear
* Tests for Retailer to assist with refactor
* Move Yelp logic into class to isolate and test logic
Add Yelp test, Convert to MiniTest:Spec syntax
Remove geocoder, upgrade geokit and implement new syntax

+ Removes Geocoder in favor of using only geokit
+ Upgrades geokit and geokit-rails
+ Updates query syntax for retreival of retailers