updated tests for empty station, added an empty station to the request.rb file
updated empty station (41) and offline station (38) test json
removed redundant tests
Initialize method now accepts a url if passed
Added JSON response with offline stations
Move JSON responses to separate files
Added more detailed checks on the response of offline stations tests
Added test to check for url passed on initialize
Merge pull request #8 from zackshapiro/lat-long

[green] Added method to get lat/long of a station