Skip failing tests until Django upgrade
Skip failing tests until Django upgrade

Some tests fail because Django 1.11 cannot work with the
more recent versions of proj4 (and consequently GEOS) that
are available for Ubuntu 20.04. These tests must wait until
the Django upgrade to be enabled again, in #3419.

WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed