Verify exercises in docker

[keiravillekode]

verify-exercises-in-docker is adapted from generic-track

Skipping parallel-letter-frequency

[fapdash]

Great idea. I think it makes sense to call this script in the CI job instead of bin/test-examples, no?

emacs-lisp/.github/workflows/ci.yml

Line 23 in a977876

bash bin/test-examples

parallel-letter-frequency test should work once exercism/emacs-lisp-test-runner#88 is merged. :)

[keiravillekode]

parallel-letter-frequency works when I limit the number of processes. I'm not sure why.

[keiravillekode]

Note that if we choose to use this for CI, we might need to wait 3 times longer for results:

time bin/test-examples
real    0m12.962s
user    0m10.093s
sys     0m4.300s

time bin/verify-exercises-in-docker
real    0m35.558s
user    0m1.278s
sys     0m2.243s