chore(package): update prettier to version 2.0.3

Closes #47

Author: greenkeeper[bot]

package.json

@@ -57,7 +57,7 @@
     "eslint-plugin-prettier": "^3.0.1",
     "husky": "^1.3.1",
     "lint-staged": "^8.1.0",
-    "prettier": "^1.15.3",
+    "prettier": "^2.0.3",
     "rimraf": "^2.6.3"
   },
   "lint-staged": {