rollback to koa-route@^2

example/spa/css/style.css

@@ -1,3 +1,5 @@
 body {
   background-color: IndianRed;
 }
+
+a { color: black }

example/spa/index.html

@@ -3,6 +3,10 @@
 </head>
 <h1>Single Page App</h1>
 <h2>Location: <span></span></h2>
+<ul>
+  <li><a href="/login">/login</a></li>
+  <li><a href="/search">/search</a></li>
+</ul>
 <script>
   document.querySelector('h2 span').textContent = window.location.pathname
 </script>