when hitting issue, the response struct should be the same as
normal response as below.
```
type Response struct {
Code int `json:"code"`
Data interface{} `json:"data"`
}
```
Fix#169
* Implement API `api/envs/default/apps/
implement API `api/envs/default/apps/ and refactor code
* address comments from @wonderflow and @ryan
* fix code rebase issue
* temporary comment BeforeSuite in integration/integration_suite_test.go to fix make issue