Merge branch 'renovate/django-celery-beat-2.x' into 'master'

Update dependency django-celery-beat to v2

See merge request AlekSIS!171

pyproject.toml

@@ -61,7 +61,7 @@ django-js-reverse = "^0.9.1"
 calendarweek = "^0.4.3"
 Celery = {version="^4.4.0", optional=true, extras=["django", "redis"]}
 django-celery-results = {version="^1.1.2", optional=true}
-django-celery-beat = {version="^1.5.0", optional=true}
+django-celery-beat = {version="^2.0.0", optional=true}
 django-celery-email = {version="^3.0.0", optional=true}
 django-jsonstore = "^0.4.1"
 django-polymorphic = "^2.1.2"