Update django from 2.2 to 2.2.2

Author: pyup-bot

requirements.txt

@@ -1,7 +1,7 @@
 boto3==1.9.135
 celery==4.3.0
 channels-redis==2.4.0
-Django==2.2
+Django==2.2.2
 django-allauth==0.39.1
 django-compressor==2.2
 django-htmlmin==0.11.0