Update internationalization.rst

Made the 'default language' line bold
Update quickstart.rst

Added -m flag for devstrap
Update quickstart.rst

Made the Node.js, Git and Python requirements linked to their websites for download.
Update quickstart.rst

Added Node.js and volo installation related notes
Added Factory Boy to create objects for tests. Refactored accounts tests to work with Factory Boy, and additionally added more accounts tests.
Merge remote-tracking branch 'origin/develop' into develop