Enable affinity configuration to schedule pod on specific nodes in cluster

[mahantsucf]

This PR helps to schedule pod on specific nodes in cluster & feature has been tested on openshift cluster. Here are the testing configurations & test results screen shots.

quarks-operator has been installed by helm by passing following affinity configuration values.

I. Label openshift cluster node

oc label node xx.xx.xx.249 cf-node-group=cf-nodes

II. Helm values as below

affinity: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms:

matchExpressions: key: cf-node-group operator: In values: cf-nodes

III. Test Results, Pod is scheduled on labeled node "xx.xx.xx.249"

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/178925521

The labels on this github issue will be updated when the story is started.