Run tests in random order

[trentmwillis]

In the docs for the reorder config option, it notes that reordering failed tests can:

also lead to random errors, in case your testsuite has non-atomic tests, where the order is important. You should fix those issues, instead of disabling reordering!

So, on a similar note, I'd like to propose adding the ability to specify that tests run in a seeded-random order. I think it would be relatively straightforward to introduce this as QUnit already has the infrastructure to reorder tests. This may not be particularly useful in browser, but could be very beneficial for CI/Post-Commit tooling looking to identify leaky/dependent tests.

As a point of reference, I looked into what other test frameworks have done in regards to this and found that this feature was recently introduced in Jasmine and has been requested multiple times for Mocha.