switch to testing

Change-Id: Iba410b7559fcb969fde3cb3963af83888f4ada98
diff --git a/init.yml b/init.yml
index 55bfa47..87fce4a 100644
--- a/init.yml
+++ b/init.yml
@@ -38,7 +38,7 @@
 - service.docker.host
 parameters:
   _param:
-    apt_mk_version: '2018.1'
+    apt_mk_version: 'testing'
     aptly_gpg_keypair_id: A8272E04
     aptly_gpg_passphrase: ""
     aptly_server_secure: true