Using an arrow function into handleClientLoad() method cause to use wrong scope

[Simone Torrisi]

I've noticed that the handleClientLoad method uses an arrow function to init the client.

script.onload = () => {
   window['gapi'].load('client:auth2', this.initClient);
};

This causes that the this scope used here is related to the arrow function, not the whole class, because of the arrow function behavior.

You can fix it switching to ES5 functions:

script.onload = function () {
   window['gapi'].load('client:auth2', this.initClient);
};