Fix typo. (#37)

REHL -> RHEL.

Author: mboldt

README.md

@@ -12,7 +12,7 @@
 * A minimum of 3 nodes which support the following [requirements][] 
 * A kubernetes version of 1.8 or higher
 * For service broker - a k8s distribution that supports service catalog (see also: [service-catalog][])
-> Note: For REHL based images and/or deployments on OpenShift, please use redis-enterprise-cluster_rhel.yaml and operator_rhel.yaml.  
+> Note: For RHEL based images and/or deployments on OpenShift, please use redis-enterprise-cluster_rhel.yaml and operator_rhel.yaml.  
 For Service Broker, please see examples/with_service_broker_rhel.yaml. RedHat certified images are available on: https://access.redhat.com/containers/#/product/71f6d1bb3408bd0d