add slack notification

Author: Gustavo Muniz do Carmo

.travis.yml

@@ -33,4 +33,6 @@ after_success:
   - ./trigger.sh codeyourinfra docker_compose master $TRAVIS_GITHUB_TOKEN
 
 notifications:
-  webhooks: https://galaxy.ansible.com/api/v1/notifications/
+  webhooks: https://galaxy.ansible.com/api/v1/notifications/
+  slack:
+    secure: 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