Update JointJS

[kevingranade]

We're on an ancient version of JointJS, it might be highly beneficial to migrate to a recent version.

See https://www.jointjs.com/opensource#Download-JointJS
See etodd@81ca494

[kevingranade]

Understatement of the year, this is so much better:
http://resources.jointjs.com/demos/devs

[oosyrag]

Changelog and migration guide for reference https://changelog.jointjs.com/plus/4.0.0/changelog

Also to clarify - was the "better" in the linked demo in regards to a specific feature or the visual presentation?

[kevingranade]

I played around with several of the demos and responsiveness, animation fluidity and looks were all much improved.