0.9.x is not compatible to 0.4.x

[TimDaub]

Describe the bug

MINOR version when you add functionality in a backwards-compatible manner, and

via https://semver.org/

As far as I can judge from the changelog, OutlineButton was refactored to a parameter on Button. This is a great change many welcome, however it's not backward-compatible according to semver.

Expected behavior Expected would be that OutlineButton remains existing until version 1.0.0 is released, I guess.

[gesquinca]

Looking into this. Thanks for raising @TimDaub!