Ahodges/doc/doc1118

@shnayder @marcotuts @mulby @stroilova @JAAkana @WatsonEmily 
Educational level demographics!
Not sure if it's worth mentioning, but there used to actually be two options presented to the user in this category. One for "STEM" PhD and the other for non-STEM PhD.

We group those two categories into just "doctorate" in the pipeline.