consolidate: improve robustness

[ES-Alexander]

Currently it's possible to break the consolidation cycle by adding a typo or problem to the Dockerfile of a new version of an accepted extension. That's problematic and relies excessive helicopter parenting of the repo.

The consolidation script should gracefully handle extension fetch failures, either by skipping the malformed data, and/or entirely skipping the version with the malformed Dockerfile. An error message should be printed out/logged whenever a failure/skip occurs.

[Williangalvani]

my goal long term is to email the maintainers. maybe opening an issue and tagging them?

[ES-Alexander]

Hmm, that definitely seems handy, but should also be opt-in functionality of the consolidate program, since you don't want to fire off emails and issues to heaps of people if you run it locally / run it on a PR where you happen to have broken the program itself.

Either way, the catching and handling errors step has to be implemented before we can meaningfully do something with them :-)

[Williangalvani]

also, this is very related to #25