Update rector/rector requirement from ^0.14 || ^0.15 || ^0.16 || ^0.17 to ^0.14 || ^0.15 || ^0.16 || ^0.17 || ^0.18

Update rector/rector requirement from ^0.14 || ^0.15 || ^0.16 || ^0.17 to ^0.14 || ^0.15 || ^0.16 || ^0.17 || ^0.18 #126