stdout/err stored on fail

[jakubmajercik]

Changelog

Cellranger log written to output log on fail

Issue ticket number and link

Closes #729

Checklist before requesting a review

• [x] I have performed a self-review of my code

• [ ] Conforms to the Contributor's guide

• Check the correct box. Does this PR contain:

  • [ ] Breaking changes
  • [ ] New functionality
  • [ ] Major changes
  • [x] Minor changes
  • [ ] Documentation
  • [ ] Bug fixes

• [ ] Proposed changes are described in the CHANGELOG.md

• [x] CI tests succeed!