Provide a new function to remove a service

[arun-gupta]

A new function to remove k8s service would be useful:

"provider": {
                "type": "python",
                "module": "chaosk8s.service.actions",
                "func": "remove_service",
                "arguments": {
                    "label_selector": "app=myapp-greeting",
                    "ns": "default"
                }
            }

FYI @adrianco