[COOK-2771] Add support for xz compressed archives 

Let's try to revive [COOK-2771](https://tickets.opscode.com/browse/COOK-2771)!

See also original pull request (#14) from @stevendanna.

Notes: 
- pull request validation by Travis CI might fail as `foo.tar.gz` file is not (yet) present in opscode-cookbooks/ark master branch.
- let me know if you prefer that I rebase this pull request without the rubocop fixes (second commit 2c4f5a6)