message: fix: change webpack build script name
diff: "scripts": {
  "clean": "rimraf lib dist",
  "babel:build": "babel src/ --out-dir lib/",
  - "build": "npm run lint && npm run clean && npm run babel:build && npm run pack",
  + "webpack:build": "webpack --env build",
  + "build": "npm run lint && npm run clean && npm run babel:build && npm run webpack:build",
  "lint": "eslint --ext .js src test",
  "test": "mocha --require @babel/register --colors ./test/**/*.spec.js",
  "test:watch": "mocha --require @babel/register --colors -w ./test/**/*.spec.js",
  - "pack": "webpack --env build",
  "test:ci": "scripts/run-test.sh",
  "testrpc": "ganache-cli --mnemonic 'clock radar mass judge dismiss just intact mind resemble fringe diary casino' --gasLimit 13000000"
  },
  