Performance optimization (#30)

* optimizing recurrent statements
* adding demo which uses no router cache

Author: jkyberneees

demos/basic-nocache.js

@@ -0,0 +1,12 @@
+const cero = require('../index')
+const { router, server } = cero({
+  router: require('../lib/router/sequential')({
+    cacheSize: 0
+  })
+})
+
+router.get('/hi', (req, res) => {
+  res.end('Hello!')
+})
+
+server.listen(3000)

lib/next.js

@@ -25,8 +25,8 @@ function next (middlewares, req, res, index, routers = {}, defaultRoute, errorHa
         req.preRouterPath = req.path
 
         req.url = req.url.replace(pattern, '')
-        if (!req.url.startsWith('/')) {
-          req.url = '/' + req.url
+        if (req.url.charCodeAt(0) !== 47) {
+          req.url = '\u002f'.concat(req.url)
         }
       }