Use image constructor in client

Replace manual image struct creation with the image
constructor which is there to do just that.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

import.go

@@ -80,10 +80,7 @@ func (c *Client) Import(ctx context.Context, importer images.Importer, reader io
 			imgrec = updated
 		}
 
-		images = append(images, &image{
-			client: c,
-			i:      imgrec,
-		})
+		images = append(images, NewImage(c, imgrec))
 	}
 	return images, nil
 }