message: Do not run tests concurrently in CI
  Improves reliability with Firefox.
diff: "scripts": {
  "postinstall": "lerna bootstrap",
  "build": "lerna run build",
  - "test": "lerna run build && lerna run test"
  + "test": "lerna run build && lerna run --concurrency 1 test"
  },
  "devDependencies": {
  "lerna": "2.0.0-beta.38"
  