Support Bash Arrays

Hi there,
I love fire but I keep running in the same issue.

A lot of my scripts support a target directive so I can handover a list and it will iterate over the list.

If I combine that with Fire I need to write ugly python lists and can not use bash magic.
E.g. I need to write `python example.py count_lines '["file00", "file01", "file02"...]'` instead of something like 'python example.py count_lines "file{00..10}"` and I can not use any tab completion.

My current workaround is adding:
```
def count_lines(files):
if isinstance(files, str):
files = files.split()
...
```
One idea was to add this line with a special param like `--use-bash-arrays` to the Fire parser so I can run the script like: `python example.py count_lines "ffiles{00..}" -- --use-bash-arrays`