message: "alternative fix" for travis-ci bug
diff: "tslint": "^6.1.3",
  "tslint-no-circular-imports": "^0.7.0",
  "typescript": "^3",
  - "uglify-js": "^2.4.11"
  + "uglify-js": "^2.4.11",
  + "yarn": "^1.17.3"
  },
  "optionalDependencies": {
  "@zxing/text-encoding": "~0.9.0"
  