(build) Setup AppVeyor Notifications to Gitter

Author: gep13

appveyor.yml

@@ -56,4 +56,14 @@ test: off
 #---------------------------------#
 
 cache:
-  - Source\packages
+  - Source\packages
+
+#---------------------------------#
+#  notifications configuration    #
+#---------------------------------#
+notifications:
+  - provider: Webhook
+    url: https://webhooks.gitter.im/e/a72ea926ecc08de68e71
+    on_build_success: true
+    on_build_failure: true
+    on_build_status_changed: true