fix: allowedMethods() should not fail if more than one router is defined (#183)

Fixes #182

Author: lbesson-della

Diff for: lib/router.js

@@ -228,7 +228,7 @@ class Router {
         ctx.routerPath;
       const matched = router.match(path, ctx.method);
       if (ctx.matched) {
-        ctx.matched.push(matched.path);
+        ctx.matched.push.apply(ctx.matched, matched.path);
       } else {
         ctx.matched = matched.path;
       }