Rename exercises dir

Name it instead "topics" so it won't be
strange if some topics included "exercises" directory.

topics/kubernetes/solutions/replicaset_01_solution.md

@@ -0,0 +1,62 @@
+## ReplicaSet 01 - Solution
+
+1. Create a ReplicaSet with 2 replicas. The app can be anything.
+
+```
+cat >> rs.yaml <<EOL
+apiVersion: apps/v1
+kind: ReplicaSet
+metadata:
+  name: web
+  labels:
+    app: somewebapp
+    type: web
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      type: web
+  template:
+    metadata:
+      labels:
+        type: web
+    spec:
+      containers:
+      - name: httpd
+        image: registry.redhat.io/rhscl/httpd-24-rhel7
+EOL
+
+kubectl apply -f rs.yaml
+```
+
+2. Verify a ReplicaSet was created and there are 2 replicas
+
+```
+kubectl get rs
+# OR a more specific way: kubectl get -f rs.yaml
+```
+
+3. Delete one of the Pods the ReplicaSet has created
+
+```
+kubectl delete po <POD_NAME>
+```
+
+4. If you'll list all the Pods now, what will you see?
+
+```
+The same number of Pods. Since we defined 2 replicas, the ReplicaSet will make sure to create another Pod that will replace the one you've deleted.
+```
+
+5. Remove the ReplicaSet you've created
+
+```
+kubectl delete -f rs.yaml
+```
+
+6. Verify you've deleted the ReplicaSet
+
+```
+kubectl get rs
+# OR a more specific way: kubectl get -f rs.yaml
+```