Within travis-ci, we have noticed several isolated cases where there are image test sha failures with the new image testing framework.

On re-running the failed travis job, all the tests pass. How disconcerting 😞

This issue has occurred on several separate PRs where the developer has not touched any image tests nor introduced any changes that would alter any image tests.

We require to investigate and fix this issue to ensure that the image testing framework is both stable and reliable, otherwise all PRs will be open to this issue.