dnadna init bugs when not using a template

Hello,

The following command crashes:

dnadna init       
an unexpected error occurred: local variable 'simulation_config' referenced before assignment; run again with --debug to view the full traceback

With debug:

dnadna init --debug output

 dnadna init --debug
an unexpected error occurred: local variable 'simulation_config' referenced before assignment; run again with --debug to view the full traceback
an unexpected error occurred: local variable 'simulation_config' referenced before assignment; run again with --debug to view the full traceback
Traceback (most recent call last):
  File "/home/jean/anaconda3/envs/dnadna/bin/dnadna", line 11, in <module>
    load_entry_point('dnadna', 'console_scripts', 'dnadna')()
  File "/home/jean/Documents/Git/dnadna/dnadna/utils/__init__.py", line 798, in main
    raise exc
  File "/home/jean/Documents/Git/dnadna/dnadna/utils/__init__.py", line 790, in main
    ret2 = cls.run_subcommand(args)
  File "/home/jean/Documents/Git/dnadna/dnadna/utils/__init__.py", line 759, in run_subcommand
    return command_cls.main(command[1:], namespace=args)
  File "/home/jean/Documents/Git/dnadna/dnadna/utils/__init__.py", line 798, in main
    raise exc
  File "/home/jean/Documents/Git/dnadna/dnadna/utils/__init__.py", line 782, in main
    ret = cls.run(args)
  File "/home/jean/Documents/Git/dnadna/dnadna/data_preprocessing.py", line 574, in run
    sim_name = simulation_config.get('simulator_name')
UnboundLocalError: local variable 'simulation_config' referenced before assignment

Although it shouldn't as per the docstring froom dnadna init --help

usage: dnadna init [-h]
                   [--list-templates | --show-template {default,one_event} | -t {default,one_event}]
                   [-c SIMULATION_CONFIG] [-m MODEL_NAME]
                   [MODELS-ROOT]

Initialize a new model training configuration and directory structure.

I expect that dnadna init creates a default directory structure and config files (training and simulation files) with default names. Using dnadna init -m my_model should behave similarly except that it uses the model "my_model".