Bump @koa/router from 12.0.1 to 13.0.0

Bumps [@koa/router](https://github.com/koajs/router) from 12.0.1 to 13.0.0.
- [Release notes](https://github.com/koajs/router/releases)
- [Changelog](https://github.com/koajs/router/blob/master/HISTORY.md)
- [Commits](koajs/router@v12.0.1...v13.0.0)

---
updated-dependencies:
- dependency-name: "@koa/router"
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

package.json

@@ -14,7 +14,7 @@
     "coverage": "jest --coverage"
   },
   "dependencies": {
-    "@koa/router": "^12.0.1",
+    "@koa/router": "^13.0.0",
     "@octokit/rest": "^20.1.1",
     "escape-goat": "^3.0.0",
     "github-username-regex": "^1.0.0",