0.2.1

CHANGES:

• Expose the ocluster-worker library in the ocluster-worker package
  (@MisterDA @art-w, #219 #217 #151, reviewed by @tmcgilchrist)
• Remove corrupted repositories from the cache (@kit-ty-kate #216, reviewed by @talex5)
• Allow workers to report additional prometheus metrics (@patricoferris #210, reviewed by @tmcgilchrist, @MisterDA)
• Smother Cap'n Proto and TLS debug logs (@MisterDA #213, reviewed by @talex5)
• Added command line option to set obuilder health check period (@mtelvers #214, reviewed by @tmcgilchrist)
• Conditionally compile macos user_temp fetcher (@tmcgilchrist #209, reviewed by @MisterDA, @mtelvers)
• Make rsync-mode mandatory when using rsync store (@tmcgilchrist #202, reviewed by @MisterDA)
• Windows service bugfixes (@MisterDA #200, reviewed by @tmcgilchrist)
• Fix build and opam metadata (@MisterDA @tmcgilchrist #199 #203)