Add external compose support in the docker role

- Use ansible.posix.synchronize for compose.yml
- Set fact for compose service restarts
- Introduce plain Docker dev host
- Optionally verify repos via GPG before sync
- Hide docker_repos_path in .folder
- Tweak .env for conciseness
- Add --diff to Ansible in Vagrantfile
- Clean output with loop_control
- Embed GPG in base role

Vagrantfile

@@ -43,5 +43,6 @@ Vagrant.configure("2") do |config|
     ENV['ANSIBLE_ROLES_PATH'] = File.dirname(__FILE__) + "/roles"
     ansible.compatibility_mode = "2.0"
     ansible.playbook = "dev/" + PLAYBOOK + ".yml"
+    ansible.raw_arguments = ["--diff"]
   end
 end