visionmedia/n — pull request #178 by yorkie (2014-06-06 06:12:22+00:00)
Title: fix #177, add a lock file for n

before the version installed, touch a file named `n.lock` in version directory, and util the version has been installed/downloaded locally, remove the file.

Then for that checking function, just check the n.lock of the corresponding version directory is existed.
/cc @tjwebb