add replication

[salehsedghpour]

Adding the replication factor for each service which could be specified by the user in each cluster.
For instance, if the user specifies:

...
"services": [
    {
      "name": "service1",
      "clusters": [
        {
          "cluster": "cluster-1",
          "replicas": 2,
          "namespace": "default",
          "node": "node-1"
        }
      ],
...

After generating such the yaml files and deploying them to the cluster, we will have:

 % kubectl get pods         
NAME                                         READY   STATUS    RESTARTS        AGE
service1-75576df8cd-6djv8   2/2          Running   0                         3m27s
service1-75576df8cd-kswrq   2/2.        Running   0                         3m27s

It closes #46 .