added ability to search on Foursque Venue ID (v2)
support + doc for the fousquare_v2_id parameter in location_search
rpec for location_search with the foursquare_v2_id param
added location search examples to the readme
Merge pull request #52 from roomnoise/search_by_foursquare_v2_id

Locations search by Foursquare V2 ID