Update dependency prettier to v1.13.7

#52

Author: renovate[bot]

package.json

@@ -20,7 +20,7 @@
     "eslint-plugin-prettier": "2.6.2",
     "jest": "22.4.3",
     "localtunnel": "1.9.0",
-    "prettier": "1.13.5"
+    "prettier": "1.13.7"
   },
   "engines": {
     "node": ">= 8.6.0"