Add goto function (#46)

* WIP

* programmatic navigation

* get tests working

* wait longer

test/app/routes/about.html

@@ -6,14 +6,21 @@
 	<h1>About this site</h1>
 
 	<p>This is the 'about' page. There's not much here.</p>
+
+	<button on:click='goto("/blog/what-is-sapper")'>What is Sapper?</button>
 </Layout>
 
 <script>
 	import Layout from './_components/Layout.html';
+	import { goto } from '../../../runtime/app.js';
 
 	export default {
 		components: {
 			Layout
+		},
+
+		methods: {
+			goto
 		}
 	};
 </script>