Refactor Rails 5.1 Compatibility Update

[JoshuaTatterton]

As of the_sortable_tree update which adds the rails 5.1 compatibility. The TheSortableTreeController::DefineDeprecatedMethods module provides the head_respond method that all the methods use.

The TheSortableTreeController::DefineDeprecatedMethods is needed in all other modules but in the current master branch it is not included in the modules that use it. So in implementation you need to include the required modules and the deprecated method module otherwise the other modules will error.

The deprecated methods module should probably be included in any module that use it to streamline implementation. PR incoming.

[yourtallness]

@JoshuaTatterton Unfortunately, version 2.7.1 which includes this fix has not been released.