Make Upgrade button optional in Learner Dashboard

[arbrandes]

There are a lot of things in Learner Dash that need to be made optional (Related Programs, Recommendations for You, Upgrade, Grade Required to Pass the Course, and Social Media Buttons), but the Upgrade button is rather critical.

[arbrandes]

@jsnwesson, do I understand correctly that this is already queued up for "pluginification"?

[jsnwesson]

@arbrandes that's correct! This sprint (3/18 - 3/29) I'll be working on making sure we know how the Upgrade button logic works and what it'll need to be turned into a plugin.