message: Pin terser to 3.15.0 until fix for bug in 3.16.0 gets merged
  (see https://github.com/terser-js/terser/pull/254)
diff: "karma-coverage-istanbul-reporter": "~1.4.2",
  "karma-jasmine": "~1.1.2",
  "karma-jasmine-html-reporter": "^0.2.2",
  + "terser": "3.15.0",
  "ts-node": "~5.0.1",
  "tslint": "~5.9.1",
  "tslint-config-standard": "~7.0.0"
  