Enable Flow on QA pages on beta labs.

Enable Flow on the specific pages
http://en.wikipedia.beta.wmflabs.org/wiki/Talk:Flow and
http://en.wikipedia.beta.wmflabs.org/wiki/Talk:Flow_QA
the latter so Flow browsertests can have a target.

Bug: 56635
Change-Id: I789fc2763e143690364894d8dd37f69e3c0a161f