This is one of the problems with early adoption - third party extensions may not catch up right away.

The way I see it, you have two options:

1. Use Unity 4.x until an extension becomes available for 5.
2. Update the extension's code yourself.

If your heart is set on using Unity 5, then you'll have to take care of these issues on a case by case basis. I suspect that static methods such as AnimationUtility.SetAnimationType have been moved to the applicable object, ie AnimationClip, in order to align with OOP principles. However, I don't have the Unity 5 beta to check, and it seems the documentation hasn't been updated for 5 yet.

This is one of the problems with early adoption - third party extensions may not catch up right away.

The way I see it, you have two options:

1. Use Unity 4.x until an extension becomes available for 5.
2. Update the extension's code yourself.

If your heart is set on using Unity 5, then you'll have to take care of these issues on a case by case basis. I suspect that static methods such as AnimationUtility.SetAnimationType have been moved to the applicable object, ie AnimationClip, in order to align with OOP principles. However, I don't have the Unity 5 beta to check, and it seems the documentation hasn't been updated for 5 yet.

Update: According to this, Spriter2Unity has been updated to be compatible with Unity 5.