Feature/sections crud

Added one of each type of CRUD method for sections module along with tests.
No, that's part of the description text we get from the canvas api. Right now, we are just getting the description of the method and placing it in the docstring. Some of the methods include text like this, I'm not sure how we want to handle it. in this case it seems easy to think of converting that to a link to the resource. I'm not sure if that's the case for all the text like this.