v0.5.0 Adds Django 2.2 Support

Merge pull request #81 from edx/BOM-1029-django22-support

Django22 Support

v0.4.8

Updated transifex to pull atleast 3% translated files instead of 10%.

v0.4.7

1. Test that tag validation catches HTML added to translations.

2. When tag validation finds differences, output should be deterministic.

v0.4.6

1. Ensure that Last-Translator is always set when pulling from
   Transifex. If there are no reviewed translations, Transifex will
   not include that header, but our validate code requires it.

2. Don't complain about obviously missing files when cleaning
   the headers of just-pulled files, and make sure that we do
   notice the files we did actually pull.

3. Ensure that Plural-Forms has a valid value when extracting.
   python-gettext will choke otherwise.

4. When creating a dummy po file, don't garble source strings in
   a way that relies on the Python dictionary order. This way the
   result will always be the same no matter the machine.

v0.4.5

Extract from .jsx files too.

v0.4.4

Added check-all (check all po files) argument to validate command.

v0.4.3

Specify Language header for generated dummy po files.

v0.4.2

Specified utf-8 encoding for .yaml file

Fix bug preventing use of --empty option with validate command

Fixes a bug that resulted in an error when the --empty option was used with the validate command.

Return non-zero exit code from validate command

Updates the validate command to return a non-zero exit code when problems are detected with translation files.