cleanup jsbin directory on server

cleanup.js

var fs = require('fs');

var semver = require('semver');

var numToKeep = process.argv[2] || 2;

var files = fs.readdirSync(__dirname).filter(function (file) {
  return file.indexOf('jsbin-v') === 0;
}).sort(function (a, b) {
  return semver.lt(a.slice(7), b.slice(7));
}).slice(numToKeep || 2).forEach(function (file) {
  console.log('Removing', file);
  fs.rmdirSync(__dirname + '/' + file);
});