message: Lock TypeScript version with tilde (~) range grammar
diff: "sinon": "^4.2.2",
  "ts-loader": "^3.5.0",
  "tslint": "^5.9.1",
  - "typescript": "^2.7.1",
  + "typescript": "~2.7.1",
  "uglify-js": "^3.3.10",
  "uglifyjs-webpack-plugin": "^1.1.8",
  "webpack": "^3.10.0",
  