v0.3.0

What's Changed

• librna-sys v0.3.0-pre.* by @fncnt in #4
• compatibility with ViennaRNA 2.7.0
• backwards compatibility with ViennaRNA >=2.5.0
• use pkg-config by default (with manual fallback using environment variables)

Full Changelog: v0.2.3...v0.3.0