Scheduled biweekly dependency update for week 42 (#844)

* Update isort from 5.5.4 to 5.6.4
* Update faker from 4.4.0 to 4.14.0
* Update pytest-django from 3.10.0 to 4.0.0

Author: pyup-bot

requirements/requirements-codestyle.txt

@@ -1,3 +1,3 @@
 flake8==3.8.4
 flake8-isort==4.0.0
-isort==5.5.4
+isort==5.6.4

requirements/requirements-testing.txt

@@ -1,8 +1,8 @@
 django-debug-toolbar==3.1.1
 factory-boy==3.1.0
-Faker==4.4.0
+Faker==4.14.0
 pytest==6.1.1
 pytest-cov==2.10.1
-pytest-django==3.10.0
+pytest-django==4.0.0
 pytest-factoryboy==2.0.3
 snapshottest==0.6.0