Restore failing sceanrio (depends on the v1.0.0 API)

This scenario started failing when the API changed. I wrongly
updated it instead of ensuring the API change was backward
compatible.

This commit reverts part of:
d66312f Move API to `acts_as_token_authentication_for Model`
Ensure API backward compatibility with v1.0.0

You can continue using `acts_as_token_authentication_handler`, but
should move to `acts_as_token_authentication_handler_for User`.

Fixes #30
Merge branch 'fix-api-backward-compatibility-with-v1-0-0'