集群name不是全部大写，调用开放api报错

[liqiangno1]

Describe the bug
当创建的集群name不是全部大写时，调用开放api会报{"code":500,"errors":["Failed to get k8s client list!"]}错误

To Reproduce
Steps to reproduce the behavior:

1. 创建集群，名称为K8s-Test
2. 调用开放接口
   http://ip:port/openapi/v1/gateway/action/get_deployment_status?deployment=...&namespace=...&cluster=K8s-Test&apikey=...
3. 返回错误信息

Expected behavior
希望返回正确的结果

Screenshots

Desktop (please complete the following information):

• OS: [Windows 10]
• Browser [fiddler]
• Version [5.0.2]

Server Version

- Dashboard version:
- Kubernetes version: 1.12.0
- Wayne version: 1.0.0
- Node.js version:
- Go version:

Additional context