Updated requirements for v2.4 release

base_requirements.txt

@@ -1,11 +1,14 @@
-Django
+# django-filter-1.1.0 breaks with Django-2.1
+Django>=1.11,<2.1
 django-cors-headers
 django-debug-toolbar
+# django-filter-2.0.0 drops Python 2 support (blocked by #2000)
 django-filter==1.1.0
 django-mptt
 django-tables2
 django-taggit
 django-timezone-field
+# https://github.com/encode/django-rest-framework/issues/6053
 djangorestframework==3.8.1
 drf-yasg[validation]
 graphviz

requirements.txt

@@ -1,8 +1,8 @@
 Django>=1.11,<2.1
-django-cors-headers==2.3.0
+django-cors-headers==2.4.0
 django-debug-toolbar==1.9.1
 django-filter==1.1.0
-django-mptt==0.9.0
+django-mptt==0.9.1
 django-tables2==1.21.2
 django-taggit==0.22.2
 django-timezone-field==2.1