Fix the deposit XML parser to have multiple authors in json output
It seems that the rest_framework_xml.parsers do not support parsing a list of elements from xml to json. Few hot-fixes available:
- https://github.com/jpadilla/django-rest-framework-xml/issues/11
- https://github.com/jpadilla/django-rest-framework-xml/pull/15
Migrated from T1131 (view on Phabricator)