slate-code and syntax highlighting

[tommhuth]

I'm following the example for slate-code but no highlighting occurs, and the following warnings are reported in the console:

As of slate@0.46, the `leaves` property of Text nodes has been removed. Instead, each text node contains a string of text and a unique set of marks and leaves are unnecessary.

As of slate@0.47 the `decoration.mark` property has been changed to `decoration.type` and `decoration.data` directly. 

Can't find anything in the docs restricting the plugin to a specific version of Slate, or am I missing something? I guess the API for Slate is still subject to sudden changes.