add PushImage()

[donhcd]

ping @vieux @aluzzardi @ehazlett

remaking #97

example code:

package main

import (
        "log"

        "github.com/donhcd/dockerclient"
)

func main() {
        docker, err := dockerclient.NewDockerClient("unix:///var/run/docker.sock", nil)
        if err != nil {
                log.Fatal(err)
        }
        log.Println(docker.PushImage("donhcd/ubuntu", "trusty", &dockerclient.AuthConfig{"donhcd", "password", "email"}))
}

[divideandconquer]

@donhcd thanks for rebasing and resubmitting this.

[vieux]

@bmangold is this working for you ?

[toli]

I'd love this functionality, happy to be your guinea pig if needed.
Is there a way to specify additional args, ie a way to force docker trust?

[bmangold]

This works for me! To use this, I installed docker 1.8.2 on an ubuntu VM ... exposed the daemon for tcp DOCKER_OPTS="--host=unix:///var/run/docker.sock --host=tcp://0.0.0.0:2376" , and then configured my goclient to talked to tcp://my_vm_host:2376. I was able to push an image and verify that it appeared in Hub.