`fmt.Errorf can be replaced with errors.New` and `fmt.Sprintf can be replaced with string addition`
Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
Now it's possible to run evacuate shard in async.
Also only one evacuate process can be in progress.
Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
