fix: redirect /foo to /foo/ during dev (close #183)

lib/app/app.js

@@ -63,6 +63,17 @@ export function createApp () {
     }
   })
 
+  // redirect /foo to /foo/
+  router.beforeEach((to, from, next) => {
+    if (!/(\/|\.html)$/.test(to.path)) {
+      next(Object.assign({}, to, {
+        path: to.path + '/'
+      }))
+    } else {
+      next()
+    }
+  })
+
   const options = {}
 
   enhanceApp({ Vue, options, router })