Icons generated with Alpha channel

[stevemoser]

The plugin should either show a warning, an error, or force the output of PNGs without the alpha channel to avoid:

iTunes Store Operation Failed

Error ITMS-90717: "Invalid App Store Icon. The App Store Icon in the asset catalog in 'YourApp.app' can't be transparent nor contain an alpha channel."

[yifan]

I tried remove_alpha option. It seems to be broken. I am getting gm mogrify: Unrecognized option (-alpha). in my option, it should use gm convert -flatten according to
#24

[mohemian-92817281]

Can confirm, seems to be broken.

[werediver]

Still broken in v0.13.0 🙁

[orkenstein]

The same for 0.15.0

[mortenholmgaard]

I got this to but figured out I had a completely wrong version of ImageMagick - ensure that you have latest version: https://imagemagick.org/script/download.php