Revert "Create a sandbox before each test and clean it up afterwards"
Revert "Create a sandbox before each test and clean it up afterwards"

This reverts commit c9ef14a1d3346ac6d4db00cbab09df0d6a5a97c4.

Since the helpers are using a sandbox of their own, we don't need to create
another one.

NiGhTTraX/react-test-buffet,NiGhTTraX/react-test-buffet,NiGhTTraX/react-test-buffet