Register ShutdownBuilder task

Register the task to shutdown the builders by themselves.

Author: humitos

readthedocs/builds/apps.py

@@ -1,6 +1,10 @@
+import logging
+
 from django.apps import AppConfig
 from django.utils.translation import ugettext_lazy as _
 
+log = logging.getLogger(__name__)
+
 
 class Config(AppConfig):
     name = 'readthedocs.builds'
@@ -11,3 +15,9 @@ def ready(self):
         from readthedocs.builds.tasks import ArchiveBuilds
         from readthedocs.worker import app
         app.tasks.register(ArchiveBuilds)
+
+        try:
+            from readthedocsext.builds.tasks import ShutdownBuilder
+            app.tasks.register(ShutdownBuilder)
+        except (ModuleNotFoundError, ImportError):
+            log.info('ShutdownBuilder task could not be imported.')