add redirect test to root (“/“)

test/app/routes/index.html

@@ -8,6 +8,7 @@
 <a href='about'>about</a>
 <a href='slow-preload'>slow preload</a>
 <a href='redirect-from'>redirect</a>
+<a href='redirect-root'>redirect (root)</a>
 <a href='blog/nope'>broken link</a>
 <a href='blog/throw-an-error'>error link</a>
 <a href='credentials?creds=include'>credentials</a>

test/app/routes/redirect-root.html

@@ -0,0 +1,7 @@
+<script>
+	export default {
+		preload() {
+			this.redirect(301, '/');
+		}
+	};
+</script>