bump to testing

Change-Id: I8208fb1f8d6f04ff24567e5542649f1e206e83b6
diff --git a/classes/cluster/mcp-day01/infra/init.yml b/classes/cluster/mcp-day01/infra/init.yml
index 1bcfb47..41700c1 100644
--- a/classes/cluster/mcp-day01/infra/init.yml
+++ b/classes/cluster/mcp-day01/infra/init.yml
@@ -6,7 +6,7 @@
     # TODO: Uncomment next line "linux_system_user_sudo: true" during the deployment.
     # Don't set it "false" before you configure sudo policies and enable power users.
     # linux_system_user_sudo: true
-    apt_mk_version: "proposed"
+    apt_mk_version: "testing"
     linux_repo_refresh_db: true
     infra_config_hostname: cfg01
     salt_minion_ca_host: ${_param:infra_config_hostname}.${_param:cluster_domain}