Update dependency koa to v2.16.0 (#92)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package-lock.json

@@ -22,7 +22,7 @@
     "dotenv": "16.4.7",
     "isomorphic-git": "1.29.0",
     "js-yaml": "4.1.0",
-    "koa": "2.15.4",
+    "koa": "2.16.0",
     "koa-bodyparser": "4.4.1",
     "koa-logger": "3.2.1",
     "nunjucks": "3.2.4",