Upgrade jupyter-server-proxy

[delgadom]

Workflow

• [ ] Closes issue #
• [ ] Notebook:worker pairing builds & passes local build, visual inspection & client.map tests
• [ ] Passes travis tests
• [ ] Image deployed on dev branch (see notebook and worker dev tags)
• [ ] Worker passes manual deployment test on compute.rhg
• [ ] Notebook+worker passes test-hub deployment
• [ ] Updates integrated into downstream images

Summary

Provide an overview of your PR here

Features

• components should be
• enumerated in bullets