…he `open()` pre-configuration. This allows the django settings module to be set from a command-line option or .pylintrc option as well as an environment variable (refs #286). This commit also uses default Django settings if none are specified, raising an error to the user to inform them that it is better to set it explicitly, but avoiding the need to raise a Fatal or RuntimeError if Django is not configured (refs #277 and #243)

…king - alternative is to manually supply a basic django settings file which seems like it would clog up the repo more than one single disable flag in the tox file

…G header

…nary dependancy on clikit, so either we have to pin isort to an earlier version or prevent checking that pylint-django can be installed with --no-binary (since, presumably, isort and therefore pylint now require binary package dependencies)

…gs and the reason for doing so