feat: add etcd module/role (#215)

- add etcd module
- add etcd role, profile and hieradata

Reviewed-on: https://git.query.consul/unkinben/puppet-prod/pulls/215

modules/etcd/templates/etcd.service.erb

@@ -0,0 +1,17 @@
+# DO NOT EDIT: This file is being managed by Puppet.
+[Unit]
+Description=etcd key-value store
+Documentation=https://github.com/etcd-io/etcd
+After=network.target
+
+[Service]
+User=<%= @user %>
+Group=<%= @group %>
+Type=notify
+ExecStart=/usr/bin/etcd --config-file <%= @config_file %>
+Restart=always
+RestartSec=10s
+LimitNOFILE=<%= @max_open_files %>
+
+[Install]
+WantedBy=multi-user.target