test_missing_lbm failing with environment upgrade

# 🐜 Bug Report
`test_missing_lbm` in `command_parse/test_integration.py` failing with the new environment upgrade. Likely due to mock allowing code to continue after `sys.exit` called. Error is that `sys.exit` is called twice

## How to reproduce
Step by step guide to reproduce the behaviour:

1. load ants/developer-68
2. add ants to pythonpath
3.run `pytest lib/ants/tests/command_parse /test_integration.py`

## Environment
I am using the ANTS/developer-68
environment.