Added support for the "prirotyClassName" field

[identw]

Added support for the "prirotyClassName" field for sentinel and redis pods

For example:

apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
  name: prod
value: 150
globalDefault: false
description: "prod"
---
apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
  name: prod
value: 500
globalDefault: false
description: "prod-databases"
---
apiVersion: databases.spotahome.com/v1
kind: RedisFailover
metadata:
  name: redis
  namespace: default
spec:
  sentinel:
    replicas: 3
    securityContext: {}
    priorityClassName: "prod"
    resources:
      requests:
        cpu: 100m
        memory: 50Mi
      limits:
        cpu: 300m
        memory: 100Mi
  redis:
    replicas: 2
    securityContext: {}
    priorityClassName: "prod-databases"
    resources:
      requests:
        cpu: 100m
        memory: 100Mi
      limits:
        cpu: 400m
        memory: 500Mi