Feature/base api method

Added a base class for api methods and implemented a READ action in the sections module for getting a list of sections for a course.
We could, but I don't think it would make it easier for the end user which is why I've avoided it here.  The API methods will have the action baked in so it's not something the user would ever have to specify directly.  So, it would really be something used internally where we'd end up asking in our client code "if action == Enum.POST" return "POST".  Perhaps you could elaborate on what it would look like.