message: build: set NODE_ENV when building
diff: "test": "jest",
  "prebuild": "yarn _exec \"rimraf dist\"",
  "build": "npm-run-all build:*",
  - "build:babel": "yarn _exec --ignore @edtr-io/demo \"babel src --extensions \\\".ts,.tsx\\\" --out-dir dist --root-mode upward --source-maps\"",
  + "build:babel": "yarn _exec --ignore @edtr-io/demo \"NODE_ENV=production babel src --extensions \\\".ts,.tsx\\\" --out-dir dist --root-mode upward --source-maps\"",
  "build:tsc": "yarn _exec --ignore @edtr-io/demo \"tsc --build src\"",
  "prebuild-demo": "yarn build",
  "build-demo": "lerna run --scope @edtr-io/demo build",
  