no v2 queue

**What is the issue you are having?**
- cann't compile

**What is BigCache doing that it shouldn't?**

**Minimal, Complete, and Verifiable Example**

When asking a question about a problem caused by your code, you will get much better answers if you provide code we can use to reproduce the problem. That code should be...

* ...Minimal – Use as little code as possible that still produces the same problem
* ...Complete – Provide all parts needed to reproduce the problem
* ...Verifiable – Test the code you're about to provide to make sure it reproduces the problem

For more information on how to provide an MCVE, please see the [Stack Overflow documentation](https://stackoverflow.com/help/mcve).

**Environment:**
- master branch
- `https://github.com/allegro/bigcache/blob/master/shard.go#L8`