Unfortunately "file:files/readable-stream-2.3.3.tgz" didn't work, since
the published version of the package referred to /Users/ben/dev/node-stubs
rather than referring to the local .tgz file. I have to conclude from this
experience that file: dependencies are never supposed to be published.
This reverts commit 9ca5b27977.
This commit is no longer needed now that core-util-is is not used by any
dependencies (thanks to our fork of readable-stream).
Loading this package triggers a ReferenceError if Buffer is not globally
defined. However, this package never uses Buffer.isBuffer, and in fact
none of this package's properties are ever used by any other packages in
meteor-node-stubs, so it seems safe to replace it with an empty stub.
