internal/test/builders: don't set EndpointSpec by default
internal/test/builders: don't set EndpointSpec by default

Also rewrite `Service()` to use the available options

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

cpuguy83/cli,docker/cli,thaJeztah/cli,docker/cli,thaJeztah/cli,cpuguy83/cli