chore(deps): update dependency prettier to v2.8.7

Author: renovate[bot]

package.json

@@ -16,7 +16,7 @@
     "@types/fs-extra": "^9.0.11",
     "@types/node": "latest",
     "opn-cli": "4.1.0",
-    "prettier": "2.0.4",
+    "prettier": "2.8.7",
     "tslint": "5.20.1",
     "tslint-config-prettier": "1.18.0"
   },