run apt-get update before install docker

defaults/main.yml

@@ -40,4 +40,4 @@ docker_daemon_options: {}
 # proxy env, if defined, env vars https_proxy and http_proxy will be injected.
 proxy_env:
   http_proxy:
-  https_proxy:
+  https_proxy:

tasks/setup-Debian.yml

@@ -1,4 +1,9 @@
 ---
+
+- name: Ensure apt cache is up-to-date.
+  apt:
+    update_cache: yes
+
 - name: Ensure old versions of Docker are not installed.
   package:
     name: