Reverted .travis.yml using std notifications

no issue

Std notifications for travis is not working well in generating slack notifications, reverted to use custom script to send Slack messages

.travis.yml

@@ -32,10 +32,7 @@ script: |
   else
     yarn ci
   fi
-notifications:
-  slack:
-    rooms:
-      - secure: KzvGpf6RFHgQ3BkppKM4OejFjJYxH60KkDDShet0a0v+j/03HF5Nx0S0Vl9O/F2dPt2qWvblKb3j9EKgB7RsoFSdZuOk7ijA9Duvn+p9RrLom0C9JxOA3ob065WAGyE0OGRm1P5H98loX/L+6oOHC4/qqGKXgz6gUdBtZBn/yo8=
-    on_success: change
-    on_failure: always
-    on_pull_requests: false
+after_failure: |
+  if [ "${TRAVIS_EVENT_TYPE}" == "cron" ]; then
+    curl -X POST --data-urlencode "payload={\"attachments\": [{\"color\": \"danger\", \"fallback\": \"Build Failure: $TRAVIS_JOB_WEB_URL\", \"title\": \"Build Failure\", \"text\": \"$TRAVIS_JOB_WEB_URL\"}]}" $SLACK_URL
+  fi