Release Candidate 1 for version 2.0 of the SPDX Jackson Store

What's Changed

• Generate a warning if attempting to serialize SPDX V3 data by @goneall in #74
• Allow usage of non-default copyManager in JacksonDeSerializer by @martin-bpw in #76
• Update to SPDX Spec 3.0.1 by @goneall in #77

New Contributors

• @martin-bpw made their first contribution in #76

Full Changelog: v2.0.0-Alpha...v2.0.0-RC1