* drop `variants` related resolveConfig functionality
More AOT code that we could get rid of!
* drop more files!
I keep finding these unused files 😅
* Update setupContextUtils.js
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
* add tests for the plugin API
* make plugin invocation optional
It could be that an object has been passed as a plugin, in that case we
will use the `handler` function from the object. If it doesn't exist,
then we will only take the `config` section out of it.