New upstream release.

• Print more debugging information when depsolving. We now store the exact requires which cause dependencies to be pulled in. The process is also made more deterministic by processing dependencies sorted.

• A lock is used when koji runroot command is executed to avoid race conditions with kerberos authentication.

• Add support for SHA512 into most places (everywhere except for inside .treeinfo).

• Automatically generating versions for artifacts is made more explicit. It now allows generating version for use with ostree.

• Configuration for images is simplified: all repos for an image can be configured with a single option.

• Replace yum.comps usage with libcomps (for Python 3 compatibility).

Better error reporting:

• when config mentions non-existing git branch
• when variant has no input packages or groups
• when variant includes non-existing comps group

Fixes for modular compose:

• compatible arches are expanded when gathering packages from modules
• avoid race condition where multiple threads accessed the same temporary directory
• write a list of RPMs into modulemd metadata

New upstream release:

• Empty directories are no longer created for variants that have no RPMs.
• There is an experimental backend for solving package dependencies using DNF instead of YUM. This is a preview for testing and quite likely not ready for production deployment.
• Modular composes can now be created.
• Task IDs are printed for all tasks no matter whether they failed or not.
• Better error reporting: all unsigned packages are reported (as opposed to only the first one).