chore(package): update prettier to version 2.0.2

Closes #19

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
     "husky": "^4.0.2",
     "lint-staged": "^9.2.1",
     "mongoose": "^5.5.12",
-    "prettier": "^1.17.1"
+    "prettier": "^2.0.2"
   },
   "engines": {
     "node": ">=6.0.0"