Replace deprecated pathutils.rmtree by FileUtils.remove_dir

[ivorbosloper]

Installing elasticsearch-full fails with a MethodDeprecatedError. Replace pathutils.rmtree by fileutils.remove_dir.
Fixes #173

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[nklkarthi]

# Move config files into etc
(etc/"elasticsearch").install Dir[libexec/"config/*"]
FileUtils.rm_r(libexec/"config")

This worked for me

[ivorbosloper]

# Move config files into etc
(etc/"elasticsearch").install Dir[libexec/"config/*"]
FileUtils.rm_r(libexec/"config")

This worked for me

Thanks @nklkarthi . Not so familiar with Ruby, there seem to be many different ways to delete a directory. The current code with rmtree is deprecated, so we should replace it with some FileUtils code....