fix README

1 job for master in 3 minutes and 38 seconds (queued for 4 seconds)
Status Name Job ID Coverage
  Test
failed build #616388

00:03:38

 
Name Stage Failure
failed
build Test
  • Installing numba (0.53.1)
• Installing scipy (1.7.1)
• Installing sympy (1.8)
• Installing tables (3.6.1)
$ mkdir -p _build/.jupyter_cache/
$ jupyter-book build --toc _toc_cas.yml --config _config_cas.yml --path-output _build/cas .
/bin/bash: line 128: jupyter-book: command not found
Cleaning up file based variables
ERROR: Job failed: exit code 1