Bump prettier from 2.1.1 to 2.1.2 in /token-swap/js (solana-labs#449)

Bumps [prettier](https://github.com/prettier/prettier) from 2.1.1 to 2.1.2.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/master/CHANGELOG.md)
- [Commits](prettier/prettier@2.1.1...2.1.2)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

token-swap/js/package.json

@@ -50,7 +50,7 @@
     "flow-bin": "0.131.0",
     "flow-typed": "^3.2.0",
     "mz": "^2.7.0",
-    "prettier": "^2.1.1",
+    "prettier": "^2.1.2",
     "semver": "^7.0.0",
     "watch": "^1.0.2"
   },