Update multistrap to track chef.

Change-Id: Idcd3e76e11c299c8dbdbc6b28c4eb1f1883a6241
diff --git a/multistrap.conf b/multistrap.conf
index aac4f36..aff9318 100644
--- a/multistrap.conf
+++ b/multistrap.conf
@@ -9,4 +9,4 @@
 [main]
 packages=MAIN_PACKAGES
 source=https://packages.cloud.google.com/apt
-suite=mendel-beaker
+suite=mendel-chef