Installs the command into yargs
function() {
      return {
        command: "migrate [options]",
        desc: "migrates a qooxdoo application to the next major version",
        usage: "migrate",
        builder: {
          "verbose": {
            alias : "v",
            describe: "enables additional progress output to console",
            type: "boolean"
          }
        },
        handler: function(argv) {
          return new qx.tool.cli.commands.Migrate(argv)
            .process()
            .catch(e => {
              console.error(e.stack || e.message);
              process.exit(1);
            });
        }
      };
    }