PiccoloCRUD has an option called read_only.
I think it's worth phasing this out in favour of an argument called methods.
It could be something like:
PiccoloCRUD(methods=[HTTP.get])
If read_only is provided in kwargs, then we can just map that to methods=[HTTP.get] and provide a deprecation warning.
It means you have more fine grained control over which methods to expose:
PiccoloCRUD(methods=[HTTP.get, HTTP.post])