v0.5.0

What's Changed

• Use stdin for sending command to bash by @jaspervdj-luminal in #31
• Directory exists condition by @curtis-fugue in #32
• Support all build variables in rule conditions by @curtis-fugue in #33
• Upgrade dependencies by @curtis-fugue in #34
• Miscellaneous Cleanup by @curtis-fugue in #35
• Multi-arch support by @curtis-fugue in #36
• Retry on HTTP errors by @curtis-fugue in #37
• Update VERSION to 0.5.0 by @curtis-fugue in #38

Full Changelog: v0.4.0...v0.5.0