Upgrade multiparty for os.tmpdir fix

spec/package.json

@@ -8,7 +8,7 @@
     "graceful-fs": "^4.1.9",
     "mkdirp": "^0.5.1",
     "mocha": "^3.1.0",
-    "multiparty": "^4.1.2",
+    "multiparty": "^4.1.3",
     "q": "^1.4.1",
     "send": "^0.14.1",
     "temp": "^0.8.3",