update redis wording to replica (#1680)

#### What type of PR is this?

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/kind bug
/kind cleanup
/kind documentation
/kind feature
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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>

examples/docker-compose-v3.yaml

@@ -3,19 +3,19 @@ version: "3"
 services:
 
   redis-master:
-    image: registry.k8s.io/redis:e2e 
+    image: registry.k8s.io/redis:e2e
     ports:
       - "6379"
 
-  redis-slave:
-    image: gcr.io/google_samples/gb-redisslave:v1
+  redis-replica:
+    image: registry.k8s.io/redis-slave:v2
     ports:
       - "6379"
     environment:
       - GET_HOSTS_FROM=dns
 
   frontend:
-    image: gcr.io/google-samples/gb-frontend:v4
+    image: registry.k8s.io/guestbook:v3
     ports:
       - "80:80"
     environment:

examples/docker-compose.yaml

@@ -7,15 +7,16 @@ services:
     ports:
       - "6379"
 
-  redis-slave:
-    image: gcr.io/google_samples/gb-redisslave:v1
+  redis-replica:
+    image: registry.k8s.io/redis-slave:v2
+
     ports:
       - "6379"
     environment:
       - GET_HOSTS_FROM=dns
 
   frontend:
-    image: gcr.io/google-samples/gb-frontend:v4
+    image: registry.k8s.io/guestbook:v3
     ports:
       - "80:80"
     environment: