[go] Rename the package from mlkube/katib to this repo

[gaocegege]

We used to place the code in https://github.com/mlkube/katib and we contributed to code to Kubeflow community, then I think we should rename the packages in the code.

[YujiOshima]

Yes, I agree.
I will rename the packages.

[gaocegege]

Thanks！ Then I assign this issue to you :0