chore(package): save eslint-plugin-prettier, lint-staged, prettier

Prettier will be used to ensure coding style is consistent.

Author: remarkablemark

package.json

@@ -41,9 +41,12 @@
     "@commitlint/config-conventional": "^6.1.0",
     "coveralls": "^3.0.0",
     "eslint": "^4.18.0",
+    "eslint-plugin-prettier": "^2.6.0",
     "husky": "^0.14.3",
     "istanbul": "^0.4.5",
+    "lint-staged": "^7.1.1",
     "mocha": "^5.0.1",
+    "prettier": "^1.12.1",
     "react": "^16",
     "react-dom": "^16",
     "standard-version": "^4.3.0",