`--from-json` throws error when trying to covert to CSV from a package id's json file

```
(scancode-toolkit) C:\Users\CYL\git\scancode-toolkit>scancode --from-json C:\Users\Projects\all-jar-info_identified.json --csv C:\Users\Projects\all-jar-info_identified.csv
Setup plugins...
Collect file inventory...
ERROR: failed to run output plugin: csv:
Traceback (most recent call last):
File "c:\users\cyl\git\scancode-toolkit\src\scancode\cli.py", line 870, in run_codebase_plugins
plugin.process_codebase(codebase, **kwargs)
File "c:\users\cyl\git\scancode-toolkit\src\formattedcode\output_csv.py", line 58, in process_codebase
write_csv(results, csv)
File "c:\users\cyl\git\scancode-toolkit\src\formattedcode\output_csv.py", line 76, in write_csv
rows = list(flatten_scan(results, headers))
File "c:\users\cyl\git\scancode-toolkit\src\formattedcode\output_csv.py", line 197, in flatten_scan
flat = flatten_package(package, path)
File "c:\users\cyl\git\scancode-toolkit\src\formattedcode\output_csv.py", line 299, in flatten_package
pack[compo_nk] = ' \n'.join(existing + [compo_val])
TypeError: coercing to Unicode: need string or buffer, list found
```