v0.3.0

• Make most jumbf_io functions crate private and move Store dependencies to Store (#37)
• Remove c2patool source now that it's in its own repo (#35)
• (MINOR) Update ManifestAssertion supporting instances (#34)
• Export top level signing functions, hide other signature details (#32)
• Add documentation for the Actions and Metadata assertions (#30)
• Rework how c2patool is configured (#28)
• Convert make_tests into a scriptable engine; rename to make_test_images (#29)
• Update thiserror requirement from >= 1.0.20, < 1.0.26 to >= 1.0.20, < 1.0.32 in /sdk (#9)
• Update base64 requirement from 0.12.2 to 0.13.0 in /sdk (#10)
• Update range-set requirement from 0.0.7 to 0.0.9 in /sdk (#13)
• Make Assertions opaque in the public SDK (#22)
• Update c2pa requirement from 0.1 to 0.2 in /c2patool (#23)