install-kubernetes: install lz4 packages

minikube has added a new "feature" which pre-loads a blob of data
with everything it needs that we can't disable, with a fallback.

we're currently downloading ~500MB and failing to use it because
it's compressed by lz4 which we don't have in images, this change
adds that to the package list.

Change-Id: If74faf2b21d564fa23253ea2eb5378457f055735

roles/install-kubernetes/tasks/main.yaml

@@ -10,10 +10,12 @@
     repo: deb http://apt.kubernetes.io/ kubernetes-xenial main
     state: present
 
-- name: Install kubernetes packages
+- name: Install kubernetes packages and dependencies
   become: yes
   apt:
-    name: kubectl
+    name:
+      - kubectl
+      - liblz4-tool
     update_cache: yes
 
 - name: Run cluster tasks