Binaries for phantomjs for the platforms we care about. Makes it easy to reference and use them from another project without having to install on every machine.
Note: this is the recommended way from the phantomjs project to manage these types of dependencies. Their logic is that it makes it easier to package and keep with projects to support CI. It does require larger checkouts and repos, but the logic seems to make sense.
When updating, please put in all platforms at the same time and keep this in the directory structure given. Extract the binary distribution into the package directory.