Expect error status in CLI test with no args passed

[yousefmoazzam]

Fixes #587

Checklist

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have made corresponding changes to the documentation

[yousefmoazzam]

The single failing test:

FAILED tests/test_ui_layer.py::test_can_read_gpu_pipeline - AssertionError: assert 'FBP3d_tomobar' == 'FBP'
  
  - FBP
  + FBP3d_tomobar

is a known one regarding the naming of recon methods having changed, and a fix is being worked on.

Since the failing test that this PR is intended to fix is now passing, I'm going to go ahead and merge this.