Add export_channels_to_kolibri_public to deploy-migrate

Catch missing chef user.

Author: rtibbles

Makefile

@@ -38,7 +38,7 @@ migrate:
 # 4) Remove the management command from this `deploy-migrate` recipe
 # 5) Repeat!
 deploy-migrate:
-	echo "Nothing to do here"
+	python contentcuration/manage.py export_channels_to_kolibri_public
 
 contentnodegc:
 	python contentcuration/manage.py garbage_collect

contentcuration/kolibri_public/management/commands/export_channels_to_kolibri_public.py

@@ -31,7 +31,11 @@ class Command(BaseCommand):
     def _republish_problem_channels(self):
         twenty_19 = datetime(year=2019, month=1, day=1)
         five_minutes = timedelta(minutes=5)
-        chef_user = User.objects.get(email="chef@learningequality.org")
+        try:
+            chef_user = User.objects.get(email="chef@learningequality.org")
+        except User.DoesNotExist:
+            logger.error("Could not find chef user to republish channels")
+            return
         channel_qs = Channel.objects.filter(
             public=True,
             deleted=False,