Clownlist silverstripe cache tests, re-record

Reviewed By: @JoelMarcey

Differential Revision: D1393634
Clownlist Laravel race-condition tests

Summary: sadpanda

I think I prefered the 'mutates fixed location on file system' ones :(

Found via https://gist.github.com/fredemmott/cf169e952163a7effcbe

Reviewed By: @JoelMarcey

Differential Revision: D1393668