Update auth0-angular.js

Works fine in other browser, but in IE script loading fails and gives this error.

To fix this, as per 
As per angular/angular.js@f078762

should change

$http.get('/foo').finally(doSomething);

To

$http.get('/foo')'finally';

(for IE8 compatible code)

Can you please make this quick change to fix issues with IE8.
Merge pull request #82 from payalcsureja/patch-1

IE8 Error fix