Adds both build and push support

This adds support for building and pushing docker containers
when you perform either `kompose convert` or `kompose up`.

Docker Compose files who have build parameters with their respective
image and build keys will automatically be both built and pushed.

examples/buildconfig/docker-compose.yml

@@ -3,5 +3,4 @@ version: "2"
 services:
     foo:
         build: "./build"
-        command: "sleep 3600"
-
+        image: docker.io/cdrage/foobar