Replace $timeout by $interval to allow tests with protractor

[gregwym]

Protractor wait for $timeout to finish before start testing. Growl ttl should use $interval instead, to enable protractor to validate the notification message.

marcorinck#43
angular/protractor#169

[k3v3n]

Any plan to fix this ?

[silbermm]

👍

[area]

This seems like a pretty obvious thing to do. Is there a reason you're hesitant, @JanStevens?

EDIT: I somehow missed the pending pull request, and you're waiting on tests to be included.