build(deps-dev): bump prettier from 1.18.2 to 2.2.1

Bumps [prettier](https://github.com/prettier/prettier) from 1.18.2 to 2.2.1.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/master/CHANGELOG.md)
- [Commits](prettier/prettier@1.18.2...2.2.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package-lock.json

@@ -55,7 +55,7 @@
     "express-graphql": "^0.12.0",
     "handlebars": "^4.7.6",
     "jest": "^24.9.0",
-    "prettier": "^1.18.2",
+    "prettier": "^2.2.1",
     "ts-jest": "^24.3.0",
     "ts-node": "^9.1.1",
     "tslint": "^6.1.3",