Use a native-dns fork to avoid the exception in OS X #8

Once tjfontaine/node-dns#63 gets merged, we
should switch back to using the original version.

package.json

@@ -46,7 +46,7 @@
   "dependencies": {
     "each-async": "^1.1.0",
     "log-symbols": "^1.0.0",
-    "native-dns": "^0.6.1",
+    "native-dns": "https://github.com/silverwind/node-dns/tarball/8b75198dd8",
     "onetime": "^1.0.0",
     "root-hints": "^0.1.0"
   },