rosetta-cli check always exits with status code 1 when using --end

[abukosek]

Describe the bug
When using the --end option to rosetta-cli check, it always exits with status code 1, even when there are no errors in the output.
This makes it difficult to use as part of an automated continuous-integration workflow or testing suite.

To Reproduce
Steps to reproduce the behavior:

1. Run rosetta-cli check --end 42; echo $?.

Expected behavior
If there are no validation errors, an exit code of 0 should be returned. Exit code 1 should be returned only if validation errors have occurred.

[patrick-ogrady]

Thanks for posting this issue. I think this is a great idea.