Use list as package name source

meta/.galaxy_install_info

@@ -0,0 +1 @@
+{install_date: 'Tue Jul  4 10:56:19 2017', version: 2.0.0}

tasks/install-with-package.yml

@@ -1,6 +1,7 @@
 ---
 - name: Install Certbot.
-  package: "name={{ certbot_package }} state=present"
+  package: "name={{ item }} state=present"
+  with_items: "{{ certbot_package }}"
 
 - name: Set Certbot script variable.
   set_fact:

vars/Ubuntu-16.04.yml

@@ -1 +1,2 @@
-certbot_package: letsencrypt
+certbot_package:
+  - letsencrypt

vars/default.yml

@@ -1,2 +1,5 @@
 ---
-certbot_package: certbot
+certbot_package:
+  - certbot
+  - certbot-apache
+  - certbot-nginx