Update dependency node-fetch to v2

Author: renovate-bot

package-lock.json

@@ -48,7 +48,7 @@
     "graphql-tag": "2.10.0",
     "jest": "23.6.0",
     "ncp": "2.0.0",
-    "node-fetch": "1.7.3",
+    "node-fetch": "2.3.0",
     "prettier": "1.13.7",
     "stats-webpack-plugin": "0.7.0",
     "url-join": "4.0.0",