Add specs for plans

Author: Lucas

lib/iugu/plan.rb

@@ -6,8 +6,9 @@ class Plan < APIResource
     include Iugu::APIDelete
 
     def self.fetch_by_identifier(identifier)
-      Iugu::Factory.create_from_response(object_type, APIRequest.request("GET", "#{url}/identifier/#{identifier}"))
+      Iugu::Factory.create_from_response(object_type,
+                                         APIRequest.request('GET',
+                                                            "#{url}/identifier/#{identifier}"))
     end
   end
-
 end