This also requires updating the required version of oauthlib; previously an
appropriate version was being installed only because it was a dependency of
the wrong twitter library.
This only affects development environments and/or hand-built
installations relying on the contents of requirements.txt.
To fix existing environments, the incorrect api needs to be explicitly
removed with `pip uninstall twitter`.
Fixes#86.
Instead, build them automatically when provision the development
environment and in update-prod-static.
(imported from commit aac8dfeaafbe872c113e5f2b6bd8f655a1af36f2)