This PR uses the "SelectorFromSet()" function which takes alabel or
selector as an argument returns all the object that uses that label or
selector. Once we get the object that uses a particular label we can
further do the delete operation on them. This is similar to "kubectl
delete <object> --selector=<key>=<value>". Also the label has been
modified from service to io.kompose.service.
If TCP is passed in as the protocol, by default, we add TCP as the
protocol within the Kubernetes or OpenShift artifacts.
By default, TCP is already selected within Kubernetes and thus having
the TCP output is redundant.
This commit checks to see if TCP has already been selected, and if it
has, ignores adding it to the list of ports.
Closes https://github.com/kubernetes-incubator/kompose/issues/392
