Common error messages

`npm WARN optional dep failed, continuing fsevents@0.2.1``

tl;dr: ignore it - it just means you don't use OS X.

comes from watchify which uses --> chokidar. Chokidar has an optional dependency to fsevents.

fsevents is a native library for file access on Mac OS and chokidar uses it to receive file events faster on OS X. So it is okay if this optional dep fails on Linux.

For more info see their package.json and the implementation