Remove replace statement in go.mod

[antoninbas]

Describe the problem/challenge you have
If a project implements an Octant plugin and imports both Octant and the K8s client-go, it is very easy to run into this "ambiguous import" issue: Azure/go-autorest#414.

Describe the solution you'd like
I am not sure why a replace directive was added to the go.mod in the first place, as this commit (849fd95) does not give an explanation, but maybe it is not required any more? I tries removing it from go.mod and running go mod tidy and it was able to pick up a more recent version of client-go which resolves the issue (thanks to this commit kubernetes/client-go@cca417f).

Anything else you would like to add:
I'm happy to open the corresponding PR if people are fine with this change.

[GuessWhoSamFoo]

related #432

[wwitzel3]

@bryanl is there any reason we can not remove the replace directive here?

[GuessWhoSamFoo]

Closed via #931