chore(package): update prettier to version 2.0.2

Closes #104

Author: greenkeeper[bot]

package.json

@@ -37,7 +37,7 @@
     "nodemon": "^2.0.2",
     "npm-check": "^5.9.2",
     "nyc": "^15.0.0",
-    "prettier": "^1.19.1",
+    "prettier": "^2.0.2",
     "should": "^13.2.3",
     "sinon": "^9.0.1"
   },