option to serialize / deserialize to yaml?

[lheagy]

Within SimPEG, we would like to create the option for users to drive their simulations / inversion from an input file. Ideally, this is simply a serialized class that we read / write from a file. We want it to be human editable, and json is tricky because it is very easy to mess up brackets and or commas and end up with an invalid file. yaml is a bit simpler as it is pretty human readable and editable. This is something we could support external from properties (e.g. having our own save / load functions), but I was wondering if there would be other use cases in which this would be valuable and potentially worth implementing at the properties level?

cc @fourndo