Improve example checking script

[bwohlberg]

Improve example checking script and add github action to run it on PRs.

[codecov]

Codecov Report

Merging #295 (64d8892) into main (70fd67f) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #295   +/-   ##
=======================================
  Coverage   94.21%   94.21%           
=======================================
  Files          53       53           
  Lines        3303     3303           
=======================================
  Hits         3112     3112           
  Misses        191      191           

Flag	Coverage Δ
unittests	94.21% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 70fd67f...64d8892. Read the comment docs.

[Michael-T-McCann]

This works on my machine, which is a big improvement over the last version.

I did get ./scriptcheck.sh: line 113: kill: (95112) - No such process after all the examples ran, not sure the cause.