Log Message:
py-django2: updated to 2.2.7

Django 2.2.7:
Fixed a crash when using a contains, contained_by, has_key, has_keys, or \ 
has_any_keys lookup on JSONField, if the right or left hand side of an \ 
expression is a key transform.
Prevented migrate --plan from showing that RunPython operations are irreversible \ 
when reverse_code callables don’t have docstrings or when showing a forward \ 
migration plan.
Fixed migrations crash on PostgreSQL when adding an Index with fields ordering \ 
and opclasses.
Restored the ability to override get_FOO_display().