Creating a Basic Success Function for Http
Though your solution would work, I would have gone for something like this:

class Net::HTTPResponse
  def success?
    false
  end
end

class Net::HTTPSuccess
  def success?
    true
  end
end


If you do keep your solution, you could simplify it to:

class Net::HTTPResponse
  def success?
    self.is_a? Net::HTTPSuccess
  end
end