Specifying name for output model

[davejacobs]

In the spirit of trying to fully automate the generation of my Haskell code (to allow me to quickly iterate on JSON design and then update the code without hand modifications), it would be awesome to be able to specify the top-level model name in the CLI command.

So if I wanted my model to be named something other than Model, I could type something like:

json-to-haskell --model-name=ActionsList

Is that something you'd be interested in adding?