Update dependency prettier to v2.8.7

Author: renovate[bot]

package.json

@@ -75,7 +75,7 @@
     "jest-watch-typeahead": "0.6.1",
     "npm": "6.14.8",
     "npm-run-all": "4.1.5",
-    "prettier": "2.1.2",
+    "prettier": "2.8.7",
     "start-server-and-test": "1.11.5"
   },
   "dependencies": {