Update faker from 2.0.4 to 3.0.0 (#745)

Author: pyup-bot

requirements/requirements-testing.txt

@@ -1,6 +1,6 @@
 django-debug-toolbar==2.1
 factory-boy==2.12.0
-Faker==2.0.4
+Faker==3.0.0
 pytest==5.3.1
 pytest-cov==2.8.1
 pytest-django==3.7.0