Update PyPI with version bump for Django 1.10 support

[cgdeboer]

Trying to rid myself of deprecation warnings for an application that uses Django 1.9. I see most of the changes called for already made in the repo. Can you update pyPi with a version bump so those changes can come downstream?

https://pypi.python.org/pypi/django-pgjson/0.3.1

django_pgjson/fields.py:105: RemovedInDjango110Warning: SubfieldBase has been deprecated. Use Field.from_db_value instead.

Thanks for help.

[mcastle]

Django 1.10 now breaks because of pgjson.

[smcoll]

In the meantime, Django 1.11 works when pip-installing the commit for #42.

requirements.txt

git+git://github.com/djangonauts/django-pgjson.git@30463d210a42b2de