The JSON specification permits duplicate keys, but doing so is almost
always nearly a mistake.
We can use the JSON lint library (added as
dev-requirement to composer), which is now also used to decode the
JSON (as it's the same step as validating the JSON).
Bug: T153507
Change-Id: Ia713a1906169333c1aa2aebdc0ed060d26428d72
If the "url" field in extension.json is pointing to mediawiki.org,
perform some extra validation steps:
* Require HTTPS
* Require the `www.mediawiki.org` canonical domain
Change-Id: I3371443d3f6c76f53437adf90a700969bba7d0e7