The >=4.0.0 syntax installs any version which is able to run depending on the requirements of the environment. Which means it will install phpunit 6 on php 7, which breaks the current test suite. Therefor the version must be limited to 5.7.20.
The >=4.0.0 syntax installs any version which is able to run depending on the requirements of the environment. Which means it will install phpunit 6 on php 7, which breaks the current test suite. Therefor the version must be limited to 5.7.20.

dreibh/planetlab-lxc-plcapi,dreibh/planetlab-lxc-plcapi,dreibh/planetlab-lxc-plcapi,dreibh/planetlab-lxc-plcapi