Issue with generate sign requests

[drewsamsen]

Using the example code in the readme and here https://github.com/badboy/cuba-u2f-demo/blob/master/app.rb#L172-L193

---

This line works

@sign_requests = u2f.authentication_requests(key_handles)

and creates and Array of U2F::SignRequest objects but the next line

@sign_requests.map(&:challenge)

throws

NoMethodError: undefined method 'challenge' for #<U2F::SignRequest:0x007fe9a58c94c0>

[drewsamsen]

Related? #31

[rst]

Absolutely related; the 0.2.0 version of U2F::SignRequest has a 'challenge' method and accessor; the 1.0.0 method does not.