This kubebuilder version allows us to specify the CRD api version
which in turn will allow us to generate CRDs using `v1` instead
of `v1beta1` which will be **removed** in kubernetes 1.22.
We also use a newer version of the kubebuilder test binaries, so
we can use the `v1` API.
Signed-off-by: Miguel Duarte Barroso <mdbarroso@redhat.com>