Make study listings async

This is a first attempt start at making things async. As an example, this makes the creation of the study listings async so the loading is non-blocking or other pages.
Looking at this more, to take full advantage of async we may want to build a dictionary of study info instead of just adding the study object, as that would unload the entirety of the DB calls to a separate async'ed function. Right now we still do a lot of the calls inside the template as the page is built. It would also be a first step in decoupling DB objects and qiita_pet. Thoughts?