updated readme with phpunit groups info
updated readme with phpunit groups info

Behat/Mink,jordi12100/Mink,talib570/Mink,Chekote/Mink,talib570/Mink,minkphp/Mink,jhedstrom/Mink,minkphp/Mink,handrus/Mink,stof/Mink,aik099/Mink,jordi12100/Mink,Chekote/Mink,ministryofjustice/Mink,jhedstrom/Mink