Recursive watch don't work on Linux

[Xstoudi]

The recursive option is only supported on macOS and Windows.

• https://nodejs.org/api/fs.html#fs_fs_watch_filename_options_listener

You should probably use node-watch to fix it. I warn you: the events emitted by node-watch are not the same than fs watch.

[gregberge]

Thanks for spotting it, I am open to PR but I will not fix it on my side. We don't have the Linux use-case.