Append on a non-existing resource should suffice to create

[michielbdejong]

The create tests currently test if Write on the resource (and Write or Append on the container) is required to create a non-existing resource. But the spec says "write operations attempt to create, delete, or modify resources; append operations attempt to create resources or add information to existing resources" so append on the resource should be enough.

[michielbdejong]

As clarified in solid/web-access-control-spec#105 this is NOT the case. Unskipping these tests back to the old behaviour.