Maintainance fix depreciation warnings (#3092)

- Fix test for EmailMessage task
 - Add tablib dependency for Wagtail ExportAdmin
 - Fix DeprecationWarning for django_table2
 - Fix depreciationwarning for beautifulSoup
 - Fix RemovedInDjango41Warning for default_app_config
 - Fix DjangoRemovedIn4.0 warning Middleware always require a function
 - Upgrade boto3 and scout-apm
 - Update pytest-cov to 4.0.0 from 3.0.0
 - Upgrade djangorestframework-api-key to 1.2.0
 - Rename “app” to “apps”