message: build app assets via package.json
diff: "build:backend": "python3 scripts/build_pyinstaller.py",
  "build:frontend": "python scripts/build_electron_app_with_builder.py",
  "release": "npm run build:backend && npm run build:frontend",
  - "build:backend:posix": "./scripts/build_pyinstaller.py",
  - "build:backend:win": "C:\\Python35\\python scripts\\build_pyinstaller.py",
  + "build:backend:posix": "./scripts/build_ot_app_assets.py",
  + "build:backend:win": "C:\\Python35\\python scripts\\build_ot_app_assets.py",
  "build:frontend:posix": "./scripts/build_electron_app_with_builder.py",
  "build:frontend:win": "C:\\Python35\\python scripts\\build_electron_app_with_builder.py",
  "dev": "webpack-dev-server --port 8090 --inline --hot --content-base ./app/renderer",
  