Version 0.21.x broken due to multimethod 2.0

[PetitLepton]

Hi, I just dump here — in case other fellows have the same issue — that version 0.21.x is currently broken because of the latest release of multimethod on December 26th. It is not used anymore by versions 0.22.x if I am not mistaken.

Cheers,
Flavien.

[cosmicBboy]

Thanks for the heads up @PetitLepton ! I knew it was a good decision to slim down pandera's dependencies :)