Fixed sentence grammar

examples/guestbook/README.md

@@ -16,7 +16,7 @@ If you are running from source, replace commands such as `kubectl` below with ca
 
 ### Step One: Fire up the redis master
 
-Note: This redis-master is *not* highly available.  Making it highly available would be a very interesting, but intricate exercise - redis doesn't actually support multi-master deployments at the time of this writing, so high availability would be a somewhat tricky thing implement, and might involve periodic serialization to disk, and so on.
+Note: This redis-master is *not* highly available.  Making it highly available would be a very interesting, but intricate exercise - redis doesn't actually support multi-master deployments at the time of this writing, so high availability would be a somewhat tricky thing to implement, and might involve periodic serialization to disk, and so on.
 
 Use (or just create) the file `examples/guestbook/redis-master-controller.json` which describes a single pod running a redis key-value server in a container: