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
Implements a kompose specific docker compose label "kompose.service.expose" which can be used to expose the specified services externally. The accepted values are of type string.
If the value is set to "true", the provider sets the endpoint automatically, and for any other value, the value is set as the hostname. If multiple ports are defined in a service, the first one is chosen to be the exposed.
Unit tests, functional tests, glide updates and docs have also been added in this commit for the related feature.
