add galaxy webhook to travis

Author: Jonathan Freedman

.travis.yml

@@ -15,3 +15,6 @@ script:
     | grep -q 'changed=0.*failed=0'
     && (echo 'Idempotence test: pass' && exit 0)
     || (echo 'Idempotence test: fail' && exit 1)
+
+notifications:
+  webhooks: https://galaxy.ansible.com/api/v1/notifications/