Django 1.10 uses the correct locales for simplified and traditional
Chinese languages. Previous versions used 'zh_CN' and 'zh_TW'
respectively while now the locales are 'zh_Hans' and 'zh_Hant'. This
commit takes care of this transition by doing the following:
- Add a missing translation zh-hans locale so that our tests pass.
- Add zh_Hans locale directory under 'static'. Case of the local name
is important, if we use 'zh_HANS' then the compiled translations
do not work under certain conditions.