2.1.0

The "clear .local" option has been renamed "reset user environment" and now relocates more stuff that can be problematic with user-installed packages (namely, .jupyter and .cache).

Additionally: we have dropped the dependency on our local kubespawner fork and are now using upstream k8s_asyncio (with a prerelease z2jh; in future we will get back on released versions of z2jh as well).