Add proxy tests

[jrdnbradford]

I used this test to verify changes I made in #179. It's a relatively simple one that uses an R notebook JupyterLab container, installs the latest open source RStudio Server, and verifies the rstudio endpoint is reachable through the proxy.

I've verified that this test fails for jupyter-rsession-proxy==2.5.0 (the affected release) but passes for code on #179 and the previous release.

This PR also removes the stale TravisCI status badge, replacing it with the new GHA badge.

Happy to make changes!

[ryanlovett]

First, this is amazing, thank you!

I left a couple of questions and comments.

Bonus points if you want to add another test that also launches a user server in a hub. 😄

[ryanlovett]

I'll process your other PR before this one, since this one will fail CI due to the problem your other PR fixes.

[jrdnbradford]

I've made some changes, including a test for a hub. I split up lab and hub tests mostly for clarity, but they can be merged if you like.

I applied your suggestions. The original http code check didn't check 3** codes because curl would fail with a 47 error code and not return the 3**. I've strengthened that bit up so that that code gets reported for debugging.

For the hub test I threw jupyterhub into the notebook container. Maybe there's some better way to do this? But it passes with the patch in #179 and fails with the affected release.

[benz0li]

@ryanlovett IMHO release v2.5.0 is a broken release due to #178.

After this is merged, there should be a new release that includes #179.

Thank you.

[ryanlovett]

@benz0li There is a 2.5.1 release on PyPI. There hasn't been a policy to publish on GitHub, and I think we should either always do it or never do it.

[benz0li]

@benz0li There is a 2.5.1 release on PyPI.

I missed that. Sorry.

There hasn't been a policy to publish on GitHub, and I think we should either always do it or never do it.

👍