Upgrade to kubectl 1.17.12

[dibi-codes]

This PR updates kubectl to 1.17.12

kubectl versions with patch versions lower than v1.18.8 v1.17.11 or v1.16.14 have issues updating CRD files, due to a bug when handling deeply nested CRDs. This bug will make kubectl apply -f [...] hang.
Ref: https://cert-manager.io/docs/installation/upgrading/upgrading-0.15-0.16/

[stefanprodan]

@dabeck can you please bump it to the latest v1.18, thanks

[dibi-codes]

@dabeck can you please bump it to the latest v1.18, thanks

Sure, I thought v1.17. was a thing in this project.

[stefanprodan]

Kubernetes 1.19 is out, our policy is to keep up with upstream and bump kubectl and packages to latest minor - 1

[dibi-codes]

Kubernetes 1.19 is out, our policy is to keep up with upstream and bump kubectl and packages to latest minor - 1

I had a quick try updating to k8s 1.18 but this breaks a lot of other dependencies as well. Sadly I dad no time to have a deeper look.

[squaremo]

kubectl was updated to 1.18.9 in #3309. I think this will fix the particular problem of updating CRD files, @dabeck. We may have to stick with packages from 1.17 for now, as noted in #3309. I'm going to close this PR, since it's probably not possible to make progress, and the substantive issue is fixed (and released in 1.21.0). Thanks!