message: chore: clean up package.json
diff: "files": [
  "build/proto",
  "build/protos",
  - "build/src",
  - "AUTHORS",
  - "CONTRIBUTORS",
  - "LICENSE"
  + "build/src"
  ],
  "keywords": [
  "google apis client",
  "presystem-test": "npm run compile",
  "system-test": "mocha build/system-test --timeout 600000",
  "samples-test": "cd samples/ && npm link ../ && npm test && cd ../",
  - "test": "nyc mocha build/test",
  + "test": "c8 mocha build/test",
  "lint": "eslint '**/*.js' && gts check",
  "predocs": "npm run compile",
  "docs": "jsdoc -c .jsdoc.js",
  "protobufjs": "^6.8.1"
  },
  "devDependencies": {
  - "@google-cloud/nodejs-repo-tools": "^3.0.0",
  "@grpc/proto-loader": "^0.5.2",
  "@types/execa": "^0.9.0",
  "@types/extend": "^3.0.0",
  "@types/sinon": "^7.0.0",
  "@types/tmp": "^0.1.0",
  "@types/uuid": "^3.4.4",
  + "c8": "^6.0.1",
  "codecov": "^3.0.0",
  "eslint": "^6.0.0",
  "eslint-config-prettier": "^6.0.0",
  "mocha": "^6.0.0",
  "mv": "^2.1.1",
  "ncp": "^2.0.0",
  - "nyc": "^14.0.0",
  "power-assert": "^1.4.4",
  "prettier": "^1.18.2",
  "proxyquire": "^2.0.0",
  