update redis wording to replica (#1680)

#### What type of PR is this?

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/kind cleanup
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We should be using replica to indicate a new node of redis.

Unfortunatley gcr still hasn't pushed another image, so we will still
have to use registry.k8s.io/redis-slave:v2

#### What this PR does / why we need it:

N/A

#### Which issue(s) this PR fixes:
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Fixes #

N/A

#### Special notes for your reviewer:

N/A

Signed-off-by: Charlie Drage <charlie@charliedrage.com>

README.md

@@ -16,10 +16,10 @@ Convert [`docker-compose.yaml`](https://raw.githubusercontent.com/kubernetes/kom
 $ kompose convert -f docker-compose.yaml
 INFO Kubernetes file "frontend-service.yaml" created
 INFO Kubernetes file "redis-master-service.yaml" created
-INFO Kubernetes file "redis-slave-service.yaml" created
+INFO Kubernetes file "redis-replica-service.yaml" created
 INFO Kubernetes file "frontend-deployment.yaml" created
 INFO Kubernetes file "redis-master-deployment.yaml" created
-INFO Kubernetes file "redis-slave-deployment.yaml" created
+INFO Kubernetes file "redis-replica-deployment.yaml" created
 ```
 
 Other examples are provided in the _examples_ [directory](./examples).