Update Chart.yaml

Author: joeyorlando

helm/oncall/Chart.yaml

@@ -2,8 +2,8 @@ apiVersion: v2
 name: oncall
 description: Developer-friendly incident response with brilliant Slack integration
 type: application
-version: 1.16.0
-appVersion: v1.16.0
+version: 1.15.6
+appVersion: v1.15.6
 dependencies:
   - name: cert-manager
     version: v1.8.0