0.2.20

What's Changed

• Parse optional short options like gnu getopt by @jridgewell in #82
• Parse options without names vector by @jridgewell in #81
• Update usage format for optional arguments by @jridgewell in #83
• Revert #81, #82, #83 by @alexcrichton in #84
• Fix current build warnings by @alexcrichton in #85
• Update support for being built in rust-lang/rust by @alexcrichton in #86

Full Changelog: v0.2.19...v0.2.20