chore(deps): update dependency prettier to v2

Author: renovate[bot]

apps/lit/package.json

@@ -44,7 +44,7 @@
     "karma-mocha": "^1.3.0",
     "lit-analyzer": "^1.1.9",
     "mocha": "^6.2.2",
-    "prettier": "^1.19.1",
+    "prettier": "^2.0.0",
     "rimraf": "^3.0.2",
     "rollup": "^1.27.13",
     "rollup-plugin-filesize": "^6.2.1",