chore(package): update @types/fluent-ffmpeg to version 2.1.1 (#554)

package.json

@@ -124,7 +124,7 @@
   "devDependencies": {
     "@types/body-parser": "1.16.3",
     "@types/express": "4.0.35",
-    "@types/fluent-ffmpeg": "2.1.0",
+    "@types/fluent-ffmpeg": "2.1.1",
     "@types/mime": "0.0.29",
     "@types/node": "7.0.23",
     "@types/request": "0.0.43",