bug: repeatedly broken assertion

When using hubtraf to spawn pods faster than a JupyterHub could handle, I ended up crashing hubtraf two or three times like through this assertion being broken. This only happened after a lot of other errors that made it clear where the limit was for the JupyterHub deployment.

https://github.com/yuvipanda/hubtraf/blob/78ab8b5ad9d09ce245f5056adebce843978c4351/hubtraf/user.py#L172-L189

Failure: kernel-stop hubtraf-32 exception:<ClientResponse(https://hub.neurohackademy.org/user/hubtraf-32/api/kernels/339cf55c-85c8-481a-81d3-00a414164acd) [403 Forbidden]>
<CIMultiDictProxy('Content-Length': '40', 'Content-Security-Policy': "frame-ancestors 'self';report-uri /hub/security/csp-report; default-src 'none'", 'Content-Type': 'application/json', 'Date': 'Tue, 21 Jul 2020 05:23:33 GMT', 'Server': 'TornadoServer/6.0.3', 'Strict-Transport-Security': 'max-age=15724800', 'X-Content-Type-Options': 'nosniff', 'X-Jupyterhub-Version': '1.1.0')>
 duration:0.49191117999725975
Traceback (most recent call last):
  File "/home/erik/miniforge3/bin/hubtraf-simulate", line 11, in <module>
    load_entry_point('hubtraf', 'console_scripts', 'hubtraf-simulate')()
  File "/home/erik/dev/contrib/yuvipanda/hubtraf/hubtraf/simulate.py", line 98, in main
    loop.run_until_complete(run(args))
  File "/home/erik/miniforge3/lib/python3.7/asyncio/base_events.py", line 583, in run_until_complete
    return future.result()
  File "/home/erik/dev/contrib/yuvipanda/hubtraf/hubtraf/simulate.py", line 44, in run
    outputs = await asyncio.gather(*awaits)
  File "/home/erik/dev/contrib/yuvipanda/hubtraf/hubtraf/simulate.py", line 29, in simulate_user
    await u.stop_server()
  File "/home/erik/dev/contrib/yuvipanda/hubtraf/hubtraf/user.py", line 173, in stop_server
    assert self.state == User.States.SERVER_STARTED
AssertionError

This issue is created as a followup to https://github.com/neurohackademy/nh2020-jupyterhub/issues/44#issue-662617572

yuvipanda / hubtraf

bug: repeatedly broken assertion #25