Update Twitter functionality from API v1

[bmclaughlin]

Our Twitter functionality needs to use Embedded Timelines or API v1.1. There is no set date for API v1 to be turned off, but they have started "blackout testing" where unauthenticated and API v1 calls are returned a "401 Gone" response.

More info:
https://dev.twitter.com/blog/planning-for-api-v1-retirement

Discussion thread:
https://dev.twitter.com/discussions/14709