This is a maintenance release that allows users who have installed a pre-v1.1 version of cert-manager using the Helm chart with --set installCRDs=true to upgrade to the v1.1 release without hitting a CRD validation issue that causes helm upgrade to fail.
If you cannot upgrade to Kubernetes v1.16 or later but wish to use the latest version of cert-manager that supports Kubernetes v1.11 - v1.15 you should upgrade to this release.
Most users should upgrade to the latest v1.2.0 release below.