Making gapi.auth.authorize accept string|array

Per the docs[1] gapi.auth.authorize accepts a lone string, as well as an array of strings. From my limited testing the any type appears to accept both string and array of string.

1: https://developers.google.com/api-client-library/javascript/reference/referencedocs#gapiauthauthorize
Merge pull request #2185 from domesticmouse/patch-2

Making gapi.auth.authorize accept string|array