Move podman refresh under the container subcommand

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

Closes: #981
Approved by: baude

cmd/podman/container.go

@@ -20,6 +20,7 @@ var (
 		pauseCommand,
 		portCommand,
 		//		pruneCommand,
+		refreshCommand,
 		restartCommand,
 		rmCommand,
 		runCommand,

cmd/podman/main.go

@@ -62,7 +62,6 @@ func main() {
 		portCommand,
 		pullCommand,
 		pushCommand,
-		refreshCommand,
 		restartCommand,
 		rmCommand,
 		rmiCommand,