chore(package): update @types/sinon to version 2.3.1 (#565)

package.json

@@ -129,7 +129,7 @@
     "@types/node": "7.0.26",
     "@types/request": "0.0.43",
     "@types/selenium-webdriver": "3.0.4",
-    "@types/sinon": "2.3.0",
+    "@types/sinon": "2.3.1",
     "@types/socket.io": "1.4.29",
     "@types/ws": "3.0.0",
     "apiai": "4.0.2",