* packagespec: remove meta.POST_PROCESSORS
- This is no longer needed in the spec file, as post-processor
definitions are now standardized and not project-specific,
as of Packagespec v0.1.4
* build: include go.{mod,sum} from go submodules
* packagespec: remove meta.POST_PROCESSORS
- This is no longer needed in the spec file, as post-processor
definitions are now standardized and not project-specific,
as of Packagespec v0.1.4
* build: include go.{mod,sum} from go submodules