Updating test suite to latest dependencies

This is the new version of #49.

This updates rspec/guard/factory_girl/rake to the latest versions. This was motivated by needing a newer guard to get around rb-fsevent not building in mac os. Guard fixed this with the listen gem which deals with all of that.

multi_json and active* are not updated in this commit

This also changes the way FakeResource works; when FakeResource is included into ActiveResource::Base it is disabled by default. It can be enabled by using the :fake_resource rspec metadata tag.