v0.22.0

Added

• libcnb:
  • A new API for working with layers has been added. See the BuildContext::cached_layer and BuildContext::uncached_layer docs for examples of how to use this API. (#814)

Changed

• libcnb:
  • The Layer trait and related types and functions have been deprecated. Please migrate to the new API. (#814)
  • Errors related to layers have been restructured. While this is technically a breaking change, buildpacks usually don't have to be modified in practice. (#814)

Fixed

• libcnb-data:
  • The working directory for launch processes specifying a WorkingDirectory::Directory value is now respected. (#831)