Integration tests fail to pickup YAML error

[glenrobson]

Is there a way to get the integration tests to fail if there is a problem with the YAML? There was the following issue with the index page which meant the main page failed to load the CSS:

IIIF/website@d5363bc

There was the following warning when Jekyll was built but it passed the GitHub actions tasks:

YAML Exception reading /Users/gmr/development/iiif/website/source/index.md: (<unknown>): did not find expected key while parsing a block mapping at line 37 column 7

[mnyrop]

Hmm that's interesting. jekyll build should be exactly the same locally and on actions.
We can try adding strict_front_matter: true in the config or running jekyll build --strict_front_matter within the actions workflows...? (h/t https://jekyllrb.com/docs/configuration/options/)

I can play around with it.