fix(package): update node-fetch to version 2.3.0

Closes #25

Author: greenkeeper[bot]

package.json

@@ -20,7 +20,7 @@
   "homepage": "https://github.com/pouchdb/add-cors-to-couchdb",
   "dependencies": {
     "lie": "^3.0.2",
-    "node-fetch": "^1.4.0",
+    "node-fetch": "^2.3.0",
     "yargs": "^7.0.1"
   },
   "bin": "./bin.js",