Revert "prevent minitest from printing a --seed run option"

Reason: on a second thought, minitest prints a seed as run option
regardless of the test order, and it actually calls srand, so
albeit it might be misleading I believe, it is the way it is and
should be left that way.

This reverts commit c15862ae0cb876d745609170f0f90a9bb9b5e0ae.