Google Drive XBlock - Fake PR for review purposes, do not merge!

@martynjames Created this PR for the review. 

Btw for the future, it's easier to create this when the first commit is empty. Also, if we want to review a series of PRs at once instead of individual PRs, it would be easier to merge the individual PRs in a branch which isn't master, and then create a PR from that branch into master when it's ready -- this way we don't need "fake" PRs at all, they represent the actual review workflow.
When I load this on my local devstack, the calendar doesn't load and I get:

> Load denied by X-Frame-Options: https://accounts.google.com/ServiceLogin?service=cl&passive=1209600&continue=https://www.google.com/calendar/embed?mode%3DMonth%26src%3Dedx.org_vme83q0j2v52mbhjncvfd5uqs8@group.calendar.google.com&followup=https://www.google.com/calendar/embed?mode%3DMonth%26src%3Dedx.org_vme83q0j2v52mbhjncvfd5uqs8@group.calendar.google.com&scc=1 does not permit framing.