message: added preversion and postversion NPM scripts
diff: "scripts": {
  "test": "jest",
  "lint:markdown": "remark . --frail",
  - "lint:js": "eslint *.js --ignore-path .gitignore"
  + "lint:js": "eslint *.js --ignore-path .gitignore",
  + "preversion": "npm test",
  + "postversion": "git push && git push --tags"
  },
  "keywords": [
  "iOS",
  