Upgrade to fabric8-client 7.5.0

[wind57]

We can't introduce the new leader election that fabric8 natively supports because of an issue :

fabric8io/kubernetes-client#7343

that was fixes in 7.5.0: https://github.com/fabric8io/kubernetes-client/milestone/88?closed=1

when that is released, we need to upgrade and continue work on leader election

[ryanjbaxter]

Hopefully that happens before we release 5.0.0. I don't see a due date on the milestone.

[wind57]

it's not really a show stopper for me, still working on a PR in this direction. We can easily get around it and when the time comes, just upgrade