Bump prettier from 1.14.2 to 1.15.3

Bumps [prettier](https://github.com/prettier/prettier) from 1.14.2 to 1.15.3.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/master/CHANGELOG.md)
- [Commits](prettier/prettier@1.14.2...1.15.3)

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

Author: dependabot-support

package-lock.json

@@ -62,7 +62,7 @@
     "babel-eslint": "^10.0.1",
     "eslint-config-xo-react": "^0.16.0",
     "gh-pages": "^1.2.0",
-    "prettier": "^1.14.2",
+    "prettier": "^1.15.3",
     "xo": "^0.18.2"
   },
   "xo": {