Remove deprecated code paths

[ryanhiebert]

Since we've just changed the name, let's go ahead and remove deprecated code, so that we can start with a bit cleaner slate.

[ryanhiebert]

@lbjay: Part of the appeal for changing the name was to drop some deprecated code. We can, of course, choose to do that later and cut a new 0.x version, but if we'd like to get it in before the first PyPI release of lti, then I'd like to get that done immediately.

I don't see harm in waiting, but I also want to give the opportunity to make that happen if you desire it.

[ryanhiebert]

I'm going to delay this work for a future release. I do want this to happen, but we'll just do it after the first release of this new project.