Save to file even if the job fails

[fam4r]

Use case: in a CI Job it would be nice to have an artifact with reported errors/warnings/etc. and also let the job fail.

At the moment, using the redirection (eg. > accessibility-report.html), pa11y-ci fails and it doesn't write anything to file.

Using pa11y-ci v2.3.0 and pa11y-reporter-html v1.0.0 in a GitLab pipeline.

[aarongoldenthal]

@fam4r If it help, this is a project I maintain for running pa11y-ci in GitLab and the README has a handful of example GitLab CI jobs.