Revert "Lock PHPUnit version to something that works for us"
Revert "Lock PHPUnit version to something that works for us"

This reverts commit 251523e9356700bc377fd12693aa813971dd1cbe.

RojerUA/paratest,ThomasDelteil/paratest,quizlet/paratest,chbiel/paratest,quizlet/paratest,brianium/paratest,brianium/paratest,chbiel/paratest,ThomasDelteil/paratest,localheinz/paratest,localheinz/paratest,RojerUA/paratest