refactor into files

README.md

@@ -42,13 +42,17 @@ Creates a new localtunnel to the specified local `port`. `fn` will be called onc
 ```javascript
 var localtunnel = require('localtunnel');
 
-localtunnel(port, function(err, tunnel) {
+var tunnel = localtunnel(port, function(err, tunnel) {
     if (err) ...
 
     // the assigned public url for your tunnel
     // i.e. https://abcdefgjhij.localtunnel.me
     tunnel.url;
 });
+
+tunnel.on('close', function() {
+    // tunnels are closed
+});
 ```
 
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