Make use of ChordableDjangoBackend

Includes edx-celeryutils, django-celery version bump

requirements/edx/base.txt

@@ -16,7 +16,7 @@ dealer==2.0.4
 defusedxml==0.4.1
 django-babel-underscore==0.5.1
 markey==0.8  # From django-babel-underscore
-django-celery==3.1.16
+django-celery==3.2.1
 django-config-models==0.1.3
 django-countries==4.0
 django-extensions==1.5.9
@@ -43,7 +43,7 @@ django-waffle==0.11.1
 djangorestframework-jwt==1.8.0
 djangorestframework-oauth==1.1.0
 edx-ccx-keys==0.2.1
-edx-celeryutils==0.1.5
+edx-celeryutils==0.2.2
 edx-drf-extensions==1.2.2
 edx-i18n-tools==0.3.7
 edx-lint==0.4.3