chore(package): update prettier to version 2.0.2

Closes #198

Author: greenkeeper[bot]

package.json

@@ -90,7 +90,7 @@
     "lint-staged": "7.2.0",
     "mocha": "^5.0.0",
     "nodemon": "^1.14.12",
-    "prettier": "^1.9.2",
+    "prettier": "^2.0.2",
     "puppeteer": "^1.2.0",
     "raf": "^3.4.0"
   },