Add failing test case for issue 69

- Updated RSpec matchers to use newer expect syntax to replace should syntax.
Fixed issue 69

On Ruby 2.0+ CGI.escapeHTML will escape single quotes to &#39; which breaks the WinRM web service. We pull out the rendered XML and unescape any single quotes before sending the request.
Merge pull request #73 from WinRb/fix-issue-69-cmd-with-apostrophe

Fix issue 69 cmd with apostrophe