Issuers should reference CA Bundle as configmap #46
Description
Currently the Issuer and ClusterIssuer reference caSecretName, but this is not legitimately a secret. CA bundles are often stored in configmaps, such as deployed via trust-manager.
It would be beneficial to allow referencing of a configmap instead of a secret when referring to a trust bundle. Allowance for a new field caConfigMapName and possibly caConfigMapKey to allow a custom configmap key.