Arvados

Sometimes we deploy a new version of Workbench 2 but users still have a tab open with the previous version, and resulting in confusion when they make bug reports about issues that were fixed in the new version.

Proposed solution:

1. packaging process generates a small static file with the deployed version number that is installed alongside the web app
2. workbench2 periodically (maybe every 5-10 minutes) checks to see if the deployed version number is different from the version number currently running
3. if so, it pops up a notification (maybe as a snackbar message?) saying something like "update available, click here to update" which includes a button that reloads the page.