[bug 876477] Add "Mark solved" button to email
[bug 881107][RTL] Mozilla Support at the top is not right-aligned
Increase delta used in assertDateTimeAlmostEqual.
[bug 801585] Make triangles clickable
[bug 880194] Use Twython for AoA tweet collection

This does a couple things:
- Adds Twython to the vendor libs
- Adds Twython's requirements to the vendor libs (oauthlib &
  request_oauthlib)
- Switches the AoA cron to use Twython instead of Tweepy