Support regular expressions for Windows registry key

[chris-rock]

This PR aims to bring support for regular expressions to our registry_key resource. A sample could look like:

control 'regex-test' do
  title "Ensure 'Always install with elevated privileges' is set to 'Disabled'"
  children = registry_key({
      hive: 'HKEY_USERS'
  }).children(/^S-1-5-21-[0-9]+-[0-9]+-[0-9]+-[0-9]{3,}\\Software\\Policies\\Microsoft\\Windows\\Installer/)
  describe children do
    it { should_not eq []}
  end
  children.each { |key|
    describe registry_key(key) do
      its('AlwaysInstallElevated') { should cmp 0 }
    end
  }
end

• support hash params as options for registry key
• allow regular expression as input params

Feedback is welcome.

cc @ksubrama @mhedgpeth

[chris-rock]

this should stay private

[arlimus]

Great improvement and feature!! 👍