message: Fix test side effects on Node 4 and 6
diff: "clean": "rimraf docs/ coverage/",
  "lint": "eslint-ci *.js test/{**/,}*.js",
  "docs": "jsdoc --configure .jsdocrc *.js",
  - "test": "jest --coverage && yarn lint && yarn spellcheck"
  + "test": "jest --runInBand --coverage && yarn lint && yarn spellcheck"
  },
  "jest": {
  "testEnvironment": "node",
  