* Remove Python 2 support
* Upgrade Python & Django versions
* Remove unsupported Django versions
* Remove unsupported Python versions
* Add Python 3.8
* Drop support for django-filter < 2
* Update LoginRequiredMixin doc link
* Remove redundant import
* Resolve RemovedInDjango40Warning warnings
* gql/graphene-django/graphene_django/tests/test_converter.py:175:
RemovedInDjango40Warning: django.utils.translation.ugettext_lazy() is
deprecated in favor of django.utils.translation.gettext_lazy().
* graphene-django/graphene_django/utils/utils.py:28:
RemovedInDjango40Warning: force_text() is deprecated in favor of
force_str().
* No need to use unicode strings with Python3
* Remove singledispatch dependency
singledispatch is inluded with Python >= 3.4, no need for external
package.
When we use the `graphql_schema` management command, the output can vary from run to run depending on arbitrary factors (because there is no guarantee made about the order used to output JSON dictionary keys). This makes it difficult to compare two schema's at different points in time.
We address this by including a new `canonical` flag to the command, which uses standard `json.dump` funcitonality to sort dictionary keys and force pretty-printed output.
