'php-5.4' cannot be removed

[jonajgs]

my app was create with php, so i need update the php version to 5.6.x, but when i try to add a new cartrigde, its say me "'php-5.4' cannot be removed" and when i try add php 5.6 "boekkooi-php-7.0.7 cannot co-exist with cartridge php-5.4 in your application"

=(