Outdated react-sortable-tree version

[ajunB7]

The dependency on react-sortable-tree is set to ^1.4.0. However, with 2.0 released, we should update the required dependency.

npm WARN [email protected] requires a peer of react-sortable-tree@^1.4.0 but none is installed. You must install peer dependencies yourself.

[fritz-c]

That is true. For these themes, I think migrating away from the style loader, as was done in the main library, would be the most logical step before updating to 2.0.0, but I don’t quite have the time to make that conversion and check everything right now.