dominictarr/lock — pull request #7 by Harrison-M (2014-11-12 21:30:10+00:00)
Title: Done should also be optional with multiple locks

Without this method, attempting to call the release function without a callback in place results in `Uncaught TypeError: Cannot call method 'apply' of undefined` at index.js:47. Please let me know if the included test is unsatisfactory, it's based on the test in test/index.js.