Release 0.3.1

See #15, release log:

• 6e54043 by @baudoliver7: fix: cache system files
• 5e613ae by @dependabot[bot]: Bump h2 from 2.0.206 to 2.1.210
• 752c705 by @baudoliver7: deps: Bump liquibase and h2
• 14359d5 by @baudoliver7: fix(cache): make file extension case insensitive

Released by Rultor 1.70.6, see build log