Bug 1461784: [release] Fix release notification on try; r=aki

The email address used for notification on try was templated,
but nothing actually evaluated the template. This applies the same
templating that applies to the message to any emails specified.

Differential Revision: https://phabricator.services.mozilla.com/D1297

taskcluster/taskgraph/transforms/release_notifications.py

@@ -33,6 +33,7 @@ def add_notifications(config, jobs):
             )
             subject = notifications['subject'].format(**format_kwargs)
             message = notifications['message'].format(**format_kwargs)
+            emails = [email.format(**format_kwargs) for email in emails]
             # Don't need this any more
             del job['notifications']