Feature/update clasp (#106)

* update to @google/clasp@2.4.0

- Add npm run open command
- Update readme to explain how to add existing script and document which works with npm run open
- Remove npm run setup:use-id command

package.json

@@ -10,7 +10,7 @@
     "test": "test",
     "login": "clasp login",
     "setup": "rimraf .clasp.json && clasp create --type sheets --title \"My React Project\" --rootDir ./dist",
-    "setup:use-id": "clasp setting rootDir dist && clasp setting scriptId",
+    "open": "clasp open --addon",
     "setup:https": "mkdirp certs && mkcert -key-file ./certs/key.pem -cert-file ./certs/cert.pem localhost 127.0.0.1",
     "build:dev": "cross-env NODE_ENV=development webpack",
     "build": "cross-env NODE_ENV=production webpack",
@@ -50,7 +50,7 @@
     "@babel/polyfill": "^7.10.4",
     "@babel/preset-env": "^7.11.0",
     "@babel/preset-react": "^7.10.4",
-    "@google/clasp": "^2.3.0",
+    "@google/clasp": "^2.4.0",
     "babel-eslint": "^10.1.0",
     "babel-loader": "^8.1.0",
     "babel-plugin-add-module-exports": "^1.0.2",