lib/mkdir: fix infinite loop on Windows. See https://github.com/substack/node-mkdirp/pull/74 and https://github.com/substack/node-mkdirp/issues/66

lib/mkdir.js

@@ -30,6 +30,7 @@ function mkdirs(p, opts, f, made) {
     }
     switch (er.code) {
       case 'ENOENT':
+        if (path.dirname(p) == p) return cb(er)
         mkdirs(path.dirname(p), opts, function (er, made) {
           if (er) cb(er, made)
           else mkdirs(p, opts, cb, made)