Default ordering option

Hi,

In this documentation
<https://www.postgresql.org/docs/9.1/queries-order.html>, it is said:

> If sorting is not chosen, the rows will be returned in an unspecified
> order. The actual order in that case will depend on the scan and join plan
> types and the order on disk, but it must not be relied on.

I would like to know if there is any way to change that to have a "real"
random behaviour.

My use case:
At Doctolib, we do a lot of automatic tests.
Sometimes, people forgot to order their queries. Most of the time, there is
no real problem on production. Let say, we display a user list without
order.
When a developer writes a test for this feature, he will create 2 users A
and B, then assert that they are displayed "[A, B]".
99% of the time the test will be ok, but sometimes, the displayed list will
be "[B,A]", and the test will fail.

One solution could be to ensure random order with an even distribution, so
that such failing test would be detected quicker.

Is that possible? Maybe with a plugin?

Thanks,
Cyril