Storage.has(key) returns true even when the key actually doesn't exist.

[yutao-huang]

Storage.has(key) returns true even when the key actually doesn't exist.

This incorrect behavior is also impacting things like authenticator.endpoints.has(...), which always mistakenly returns true for an actually not registered endpoint.

I have a pull-request to address this: #125. Could someone help to take a look?

Thanks!