Cache a few directories
Cache a few directories

This should speed up the build process and reduce the number of failed
builds caused by network issues during phantomjs downloads

Huggle77/4minitz,Huggle77/4minitz,RobNeXX/4minitz,4minitz/4minitz,RobNeXX/4minitz,4minitz/4minitz,RobNeXX/4minitz,Huggle77/4minitz,4minitz/4minitz