test: enable headless browsers by default
test: enable headless browsers by default

marekmicek/material,angular/material,marekmicek/material,angular/material,clshortfuse/material,clshortfuse/material,bluebirdtech/material,clshortfuse/material,bluebirdtech/material,bluebirdtech/material,marekmicek/material,oostmeijer/material,angular/material,marekmicek/material,oostmeijer/material,oostmeijer/material,oostmeijer/material,angular/material,bluebirdtech/material,clshortfuse/material