chore(package): update prettier to version 2.0.4

Closes #30

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
     "nock": "10.0.6",
     "node-typescript": "0.1.3",
     "nyc": "14.1.1",
-    "prettier": "1.18.2",
+    "prettier": "2.0.4",
     "rewire": "4.0.1",
     "source-map-support": "0.5.12",
     "superagent-mock": "3.7.0",