Update net-ssh dep to v2.2.2

[patcon]

Hey! Just trying to use this in a bundle with librarian (which requires v2.2.2 of net-ssh), and since you use ~>2.1.4, it won't work. The official release of Chef 0.10.8 is also incompatible with librarian, but the upgraded the net-ssh dep to get it working with librarian, and I just use that commit in my Gemfile:

gem "chef",
  :git => "https://github.com/opscode/chef.git",
  :ref => "ba4d58f4223"
gem "vagrant"
gem "vagrant-hosts",
  :git => "https://github.com/dwt/vagrant-hosts.git"

But I get this:

Bundler could not find compatible versions for gem "net-ssh":
  In Gemfile:
    vagrant-hosts (>= 0) ruby depends on
      net-ssh (~> 2.1.4) ruby

    chef (>= 0) ruby depends on
      net-ssh (2.2.2)

Would you be willing to accept a pull request?

[dwt]

Sure.

Also I need to change the code that establishes the hosts to the system to use Augeas - pull requests for that would also be welcomed. :)