Merge pull request #12 from ipfs/update/deps

 update merkle-dag dep

Author: daviddias

package.json

@@ -59,7 +59,7 @@
     "async": "^1.5.2",
     "debug": "^2.2.0",
     "ipfs-blocks": "^0.1.0",
-    "ipfs-merkle-dag": "^0.2.1",
+    "ipfs-merkle-dag": "^0.3.0",
     "ipfs-unixfs": "^0.1.0",
     "through2": "^2.0.0"
   }