code: function getUrls (opts) {
  
      var list    = [];
  
      var bsLocal = require("url").parse(opts.urls.local);
  
      list.push([bsLocal.protocol + "//", bsLocal.hostname, ":", opts.port].join(""));
  
      if (opts.urls.external) {
          var external = require("url").parse(opts.urls.external);
          list.push([bsLocal.protocol + "//", external.hostname, ":", opts.port].join(""));
      }
  
      return Immutable.List(list);
  }
docs: Get local + external urls with a different port
  @param opts
  @returns {List<T>|List<any>}