0.4.0-rc3

Added

• Go: Added set data structures
• Go: Added contextual SysFlow record to capture provenance information
• Pynb: Added new notebook on MITRE ATT&CK tagging and visualization

Changed

• BREAKING Go: renamed the unions in golang classes
• Pynb: restrictured working directory for SysFlow notebooks
• Pynb: updated base Jupyter image, making Jupyter lab the default environment for SysFlow notebooks (see updated usage in README.md)

Security

• Update github.com/containers/storage to fix CVE-2021-20291