Bump prettier from 1.18.2 to 2.1.1

Bumps [prettier](https://github.com/prettier/prettier) from 1.18.2 to 2.1.1.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/master/CHANGELOG.md)
- [Commits](prettier/prettier@1.18.2...2.1.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -32,6 +32,6 @@
     "jsdoc": "3.6.3",
     "jshint": "2.10.2",
     "onchange": "6.1.0",
-    "prettier": "1.18.2"
+    "prettier": "2.1.1"
   }
 }