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.

script/test/fixtures/etherpad/output-os.json

@@ -110,14 +110,6 @@
                   }
                 ],
                 "env": [
-                  {
-                    "name": "DB_DBID",
-                    "value": "etherpad"
-                  },
-                  {
-                    "name": "DB_HOST",
-                    "value": "mariadb"
-                  },
                   {
                     "name": "DB_PASS",
                     "value": "etherpad"
@@ -129,6 +121,14 @@
                   {
                     "name": "DB_USER",
                     "value": "etherpad"
+                  },
+                  {
+                    "name": "DB_DBID",
+                    "value": "etherpad"
+                  },
+                  {
+                    "name": "DB_HOST",
+                    "value": "mariadb"
                   }
                 ],
                 "resources": {}