How to show the differences between schema versions?

[robsonpeixoto]

When you are changing an API is really useful show all changes to help the developer detect breaking changes.
Is there a way to it?

A very good example in action:

➜ elm diff mdgriffith/elm-style-animation 3.5.5 4.0.0
This is a MAJOR change.

---- Animation - MAJOR ----

    Added:
        type alias Color = { red : Int, green : Int, blue : Int, alpha : Float }
        renderPairs : Animation msgA -> List ( String, String )

    Changed:
      - easing : { duration : Time, ease : Float -> Float } -> Interpolation
      + easing :
            { duration : Milliseconds, ease : Float -> Float } -> Interpolation

      - wait : Time -> Step msg
      + wait : Posix -> Step msg

I create this issue core-api/python-client#175 but make more sense create here.