Removed constant MariaDBClusterRecommendedVersion (#722)
Removed constant MariaDBClusterRecommendedVersion (#722)

Signed-off-by: Alif Biswas <707fb7d2aac6a040c4e13ca3caff4a2ba9c0308d@appscode.com>
k8sdb/apimachinery,k8sdb/apimachinery