gapi.auth2.init deprecated

[MilosZmijanjac]

Google is shutting down gapi.auth2 support and all users using this library will be rejected

[antony]

ergh. google google google.

/cc @beyonk-adventures/engineering

[dextermb]

Thanks for the heads up @MilosZmijanjac.
We'll look into upgrading our package to support other authentication methods