KeyError upon running odevalidator with `good_AltValPercent.json` file

[dmccoystephenson]

Upon running the good_AltValPercent.json file through the odevalidator, the check is interrupted by a KeyError.

Command:

python -m odevalidator --data-file tests/test-files/good_AltValPercent.json --config odevalidator/configs/config.ini

Output:

Running test on tests/testfiles/good_altValPercent.json
Traceback (most recent call last):
File "/usr/lib/python3.8/runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "/usr/lib/python3.8/runpy.py", line 87, in _run_code
exec(code, run_globals)
File "(redacted)/ode-output-validator-library/odevalidator/main.py", line 29, in
results = TestCase(args.config_file_path).validate_queue(msg_queue)
File "(redacted)/ode-output-validator-library/odevalidator/validator.py", line 445, in validate_queue
sorted_list = sorted(msg_list, key=lambda msg: msg['metadata']['serialId']['serialNumber'])
File "(redacted)/ode-output-validator-library/odevalidator/validator.py", line 445, in
sorted_list = sorted(msg_list, key=lambda msg: msg['metadata']['serialId']['serialNumber'])
KeyError: 'metadata'