fix #5 (comment)

Author: daviddias

lib/mfs.js

@@ -22,7 +22,11 @@ module.exports = function (node) {
 
     bufferStream.on('end', function () {
       // nested, must make sure we have all the dirs along the way
-      if (opts.key.indexOf('/')) {
+      // https://github.com/ipfs/ipfs-blob-store/pull/5#discussion_r44748249
+      if (opts.key[0] === '/') {
+        opts.key = opts.key.slice(1)
+      }
+      if (opts.key.indexOf('/') > -1) {
         var dirPath = opts.key.split('/')
         dirPath.pop()
         dirPath = dirPath.join('/')