Merge pull request #5076 from JayBeale/patch-3

Requesting SIG-Security channel

Author: k8s-ci-robot

communication/slack-config/channels.yaml

@@ -319,6 +319,7 @@ channels:
   - name: sig-node-rkt
   - name: sig-scalability
   - name: sig-scheduling
+  - name: sig-security
   - name: sig-service-catalog
   - name: sig-testing
   - name: sig-ui