new activitypub-testing test: post-outbox-server-overwrites-id-property

I added a new test rule for activitypub-testing.

The rule tries to find evidence that the test subject satisfies this requirement, which says:

If an Activity is submitted with a value in the id property, servers MUST ignore this and generate a new id for the Activity.

  • activitypub
  • blog
  • activitypubTesting
  • activitypub-testing