Models as Batch Jobs

[MattToast]

Allows users to launch individual models through an experiment as a batch job with batch settings.

exp = Experiment(...)
rs = exp.craete_run_settings(...)
bs = exp.create_batch_settings(...)
model = exp.create_model("MyModel", rs, batch_settings=bs)
exp.start(model)  # launches the model as a batch job

If a model with batch settings is added to a higher order entity (e.g. an ensemble), the batch settings of the higher order entity will be used and the batch settings of the model will be ignored to avoid an "sbatch-in-sbatch" scenario or similar .

[MattToast]

Closing as this branch was accidentally pushed to the main repo. It has been re-opened here: #245