Migrate apiVersion to support k8s 1.16+
Migrate apiVersion to support k8s 1.16+

Fixes #1977

Signed-off-by: Naoki Oketani <955d3c1512850e4184269be73bf0b55044b37096@gmail.com>

tsandall/opa,open-policy-agent/opa,tsandall/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa,open-policy-agent/opa,tsandall/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa,open-policy-agent/opa