Drop ruby 1.8/1.9.2 support

 * 1.8 isn't supported anymore and 1.9.3 support remains
 * Rather than having to lock to older version of rest-client for testing
Expects boolean so return false if controller doesn't match
Rspec 3
Add has_privileges_of? method

 * Allows you to know if a user has all the privileges of another
   Useful if you want to allow users to login as lesser privileged users