def http_proxy(addr = nil, port = nil, user = nil, pass = nil)
      default_options[:http_proxyaddr] = addr
      default_options[:http_proxyport] = port
      default_options[:http_proxyuser] = user
      default_options[:http_proxypass] = pass
    end
def http_proxy(addr = nil, port = nil, user = nil, pass = nil)
      default_options[:http_proxyaddr] = addr
      default_options[:http_proxyport] = port
      default_options[:http_proxyuser] = user
      default_options[:http_proxypass] = pass
    end
Allows setting http proxy information to be used

   class Foo
     include HTTParty
     http_proxy 'http://foo.com', 80, 'user', 'pass'
   end