message: Update all devDependencies and pin exact versions.
diff: "source-map": "~0.6.1"
  },
  "devDependencies": {
  - "@babel/core": "^7.4.0",
  - "@babel/parser": "^7.4.2",
  - "@babel/preset-env": "^7.4.2",
  - "@types/esprima": "^4.0.2",
  - "@types/glob": "^7.1.1",
  - "@types/mocha": "^5.2.5",
  - "@types/node": "^10.12.21",
  - "esprima-fb": "^15001.1001.0-dev-harmony-fb",
  - "flow-parser": "^0.95.1",
  - "glob": "^7.1.3",
  - "mocha": "^6.0.2",
  - "reify": "^0.18.1",
  - "ts-add-module-exports": "^1.0.0",
  - "ts-emit-clean": "^1.0.0",
  - "ts-node": "^7.0.1",
  - "typescript": "^3.3.4000"
  + "@babel/core": "7.4.4",
  + "@babel/parser": "7.4.4",
  + "@babel/preset-env": "7.4.4",
  + "@types/esprima": "4.0.2",
  + "@types/glob": "7.1.1",
  + "@types/mocha": "5.2.6",
  + "@types/node": "12.0.0",
  + "esprima-fb": "15001.1001.0-dev-harmony-fb",
  + "flow-parser": "0.98.1",
  + "glob": "7.1.4",
  + "mocha": "6.1.4",
  + "reify": "0.18.1",
  + "ts-add-module-exports": "1.0.0",
  + "ts-emit-clean": "1.0.0",
  + "ts-node": "8.1.0",
  + "typescript": "3.4.5"
  },
  "engines": {
  "node": ">= 4"
  