Added option to force use of JSON gem even if ActiveSupport::JSON is …

…present, in a backwards-compatible way.

lib/contacts/yahoo.rb

@@ -6,7 +6,6 @@
 require 'net/https'
 require 'uri'
 require 'yaml'
-require 'json' unless defined? ActiveSupport::JSON
 
 module Contacts
   # = How I can fetch Yahoo Contacts?
@@ -105,12 +104,12 @@ def get_authentication_url
     # * path <String>:: The path of the redirect request that Yahoo sent to you
     # after authenticating the user
     #
-    def contacts(path)
+    def contacts(path, force_json_gem=false)
       validate_signature(path)
       credentials = access_user_credentials()
       parse_credentials(credentials)
       contacts_json = access_address_book_api()
-      Yahoo.parse_contacts(contacts_json)
+      Yahoo.parse_contacts(contacts_json, force_json_gem)
     end
 
     # This method processes and validates the redirect request that Yahoo send to
@@ -206,11 +205,12 @@ def access_address_book_api
     # ==== Parameters
     # * json <String>:: A String of user's contacts in JSON format
     #
-    def self.parse_contacts(json)
+    def self.parse_contacts(json, force_json_gem=false)
       contacts = []
-      people = if defined? ActiveSupport::JSON
+      people = if !force_json_gem && defined? ActiveSupport::JSON
         ActiveSupport::JSON.decode(json)
       else
+        require 'json'
         JSON.parse(json)
       end