Lockfile sorting is different on different platforms

[yunxing]

Do you want to request a feature or report a bug?
bug

What is the current behavior?
When calling yarn install on Linux, it changes the order of the dependencies in the lock file thus create a diff which is unnecessary.

If the current behavior is a bug, please provide the steps to reproduce.
On linux:

git clone https://github.com/facebook/infer; cd infer
yarn install
git diff

Notice how the lockfile got changed

What is the expected behavior?
lockfile shouldn't change

Please mention your node.js, yarn and operating system version.
Linux
node v4.3.2
yarn v0.15.0

[vinnymac]

Dupe of #1168