build(deps-dev): bump size-limit from 2.1.2 to 2.1.6

Bumps [size-limit](https://github.com/ai/size-limit) from 2.1.2 to 2.1.6.
- [Release notes](https://github.com/ai/size-limit/releases)
- [Changelog](https://github.com/ai/size-limit/blob/master/CHANGELOG.md)
- [Commits](ai/size-limit@2.1.2...2.1.6)

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

package.json

@@ -33,7 +33,7 @@
     "jest": "^24.9.0",
     "jsdoc-to-markdown": "^5.0.1",
     "markdown-toc": "^1.2.0",
-    "size-limit": "^2.1.2",
+    "size-limit": "^2.1.6",
     "sloc": "^0.2.1",
     "webpack": "^4.39.3",
     "webpack-bundle-analyzer": "^3.4.1",