upgrade to box-node-sdk v1.21.0

Author: boneskull

box/package-lock.json

@@ -3,7 +3,6 @@
     "version": "0.1.3",
     "description": "Node-RED nodes to watch, download and save files to Box",
     "dependencies": {
-        "box-node-sdk": "^1.19.0",
         "minimatch": "^3.0.4",
         "request": "~2.85.0"
     },
@@ -26,5 +25,8 @@
         "name": "Mark Hindess",
         "email": "[email protected]",
         "url": "http://nodered.org"
+    },
+    "devDependencies": {
+        "box-node-sdk": "^1.21.0"
     }
 }