Using IPv6 causes application crash
/usr/lib/node_modules/ucoin/server.js:326
server6.createServer(app).listen(conf.port, conf.ipv6, function(){
^
TypeError: Object #<Server> has no method 'createServer'
at /usr/lib/node_modules/ucoin/server.js:326:19
at fn (/usr/lib/node_modules/ucoin/node_modules/async/lib/async.js:579:34)
at Object._onImmediate (/usr/lib/node_modules/ucoin/node_modules/async/lib/async.js:495:34)
at processImmediate [as _immediateCallback] (timers.js:330:15)