Renaming DirectionsServicesHelper to DirectionsRetriever

* also emptied .ruby-version; why was anything in here?
Merge branch 'master' of https://github.com/LightningLord/errandsontheway into rename-directions-service

Conflicts:
	spec/controllers/options_controller_spec.rb
Merge pull request #141 from LightningLord/rename-directions-service

Rename directions service