Add success notification emails.

Enable RevisionMixin for EventAuthorisation.

Add signal receivers for RIGS.

Expand RIGS into an explicitly defined app to support signals.

RIGS/signals.py

@@ -0,0 +1,34 @@
+import reversion
+
+from django.core.mail import EmailMessage
+from django.template.loader import get_template
+
+from RIGS import models
+
+
+def send_eventauthorisation_success_email(instance):
+    context = {
+        'object': instance,
+    }
+    client_email = EmailMessage(
+        "N%05d | %s - Event Authorised".format(instance.event.pk, instance.event.name),
+        get_template("RIGS/eventauthorisation_client_success.txt").render(context),
+        to=[instance.email]
+    )
+    mic_email = EmailMessage(
+        "N%05d | %s - Event Authorised".format(instance.event.pk, instance.event.name),
+        get_template("RIGS/eventauthorisation_mic_success.txt").render(context),
+        to=[instance.event.mic.email]
+    )
+
+    client_email.send()
+    mic_email.send()
+
+
+def on_revision_commit(instances, **kwargs):
+    for instance in instances:
+        if isinstance(instance, models.EventAuthorisation):
+            send_eventauthorisation_success_email(instance)
+
+
+reversion.post_revision_commit.connect(on_revision_commit)