Add tests for `nagios::nrpe` recipe.

This commit refs #28.
Merge branch 'id/28' into dev
Open 22/tcp port in order to access via SSH.

While CI testing inside Docker container,
the docker container's SSH daemon opens 10022 and iptables blocks 10022.

As a workaround to this proble,
open 22/tcp when CI testing.

This commit fixes #261.
Merge branch 'id/261' into dev
Specifies SSH port to be 10022/tcp.

This commit fixes #261.
Merge branch 'id/261' into dev
Modify Rakefile to enable CI testing.

This commit fixes #261.
Merge branch 'id/261' into dev
Revert "Modify Rakefile to enable CI testing."

When former change was done,
`docker restart` command seems not to be required.

In fact, it is. So, reverting the previous commit.

This reverts commit 247986894dc68484a1bb61bdbf0f9a297b92fa40.
Enable kazu634 to execute `iptables-restore` command while CI testing.

Inside Docker container, iptables configuration cannot be applied.

In order to workaround this problem,
the solution is:

  Execute the `iptables-restore` command when logged in as kazu634,
  without asking password.

By enabling kazu634 to execute `iptables-restore` command without asking password,
add entry to /etc/sudoers.d/kazu634.

see also:

- [sshでログインしたときにコマンドを実行する方法](http://kaworu.jpn.org/kaworu/2007-10-19-1.php)
- [特定のコマンドをパスワードなしでsudo する設定 - Slow Dance](http://d.hatena.ne.jp/LukeSilvia/20080716/p1)

This commit fixes #261.
Merge branch 'id/261' into dev
Move the order of adding `sudo` configuration.

After generating /etc/sudoers.d/kazu634,
add `sudo` configuration wheh CI testing.

This commit refs #261.
Merge branch 'id/261' into dev
Delete `sudo` configuration.

serverspec automatically answers `sudo` password,
so remove the unnecessary `sudo` configuration.

This commit fixes #261.
Merge branch 'id/261' into dev