0.4.2

• CVE remediations:
  • OCI Manifest Type Confusion Issue
  • Ambiguous OCI manifest parsing
  • Clarify mediaType handling
  • Insufficiently restricted permissions on plugin directories
• upgrades:
  • switched to Go 1.17
  • Ubuntu 20.04 and Alpine 3.14 to latest container images
• fixes:
  • building on non-Linux platforms (issue #61)