Add vibrate support back in

[admwx7]

Issue #55 pointed out an issue for us with using vibrate, a PR removed the functionality since it's passed the deprecation point and support was removed, however we want this functionality. Just need to figure out a way to do it that's not broken.

https://github.com/bendavis78/paper-time-picker/pull/57/files was the original code for it that was removed, for reference.

[bendavis78]

Honestly I'm curious why the Chrome warning gets triggered at all, since the vibrate occurs during a user gesture (hence not an abuse of navigator.vibrate()). Perhaps this points to a bug in Chrome?

[admwx7]

That's possible @bendavis78 I'll have to poke around at it and see what I can find, if it's still looking like a bug I'll reach out to the Polymer team on slack and see if they've encountered the like before.