Add 'kpod images' and 'kpod rmi' commands

'kpod images' lists all images on a system.  'kpod rmi' removes
one or more images from a system.  The images will not be removed
if they are associated with a running container, unless the -f
option is used

Signed-off-by: Ryan Cole <rcyoalne@gmail.com>

cmd/kpod/main.go

@@ -22,7 +22,9 @@ func main() {
 	app.Version = Version
 
 	app.Commands = []cli.Command{
+		imagesCommand,
 		launchCommand,
+		rmiCommand,
 		tagCommand,
 		versionCommand,
 		pullCommand,
@@ -45,6 +47,24 @@ func main() {
 			Usage: "used to pass an option to the storage driver",
 		},
 	}
+	app.Flags = []cli.Flag{
+		cli.StringFlag{
+			Name:  "root",
+			Usage: "path to the root directory in which data, including images,  is stored",
+		},
+		cli.StringFlag{
+			Name:  "runroot",
+			Usage: "path to the 'run directory' where all state information is stored",
+		},
+		cli.StringFlag{
+			Name:  "storage-driver, s",
+			Usage: "select which storage driver is used to manage storage of images and containers (default is overlay2)",
+		},
+		cli.StringSliceFlag{
+			Name:  "storage-opt",
+			Usage: "used to pass an option to the storage driver",
+		},
+	}
 
 	if err := app.Run(os.Args); err != nil {
 		logrus.Fatal(err)