Log Message:
Update transifex-client to 0.12.1

0.12.2

* better proxy support.

0.12.1

* Support new style URLs.
* Better error handling.

0.12b

* Fix support for downloading docx, xlsx.

0.12

* Various fixes.
  (Please refer https://github.com/transifex/transifex-client/compare/0.11...0.12)

0.11

Major changes:

* Fix bug of resource not being created automatically if it doesn't exists
* Python 3 support
* Active SSL for urllib3
* Enabled CircleCI and AppVeyor for CI testing