Build JSON API changes

None

Bug Fixes

the Koji build.extra.image.help metadata value was incorrect in 1.6.25 but has now been fixed
base image is being tagged with a unique label (build ID) to prevent base image to be removed too early having several builds running in parallel on the same node
Koji integration: if the parent image does not have expected OSBS labels, the Koji check is skipped
Different values for equal-preference label aliases no longer cause the build to fail
When Koji and Pulp integration were both enabled, the reported image ID was incorrect because pulp_pull ran after koji_upload

orchestrate_build will pass is_auto param to each worker build to help identify autorebuilds.
python-docker-2.x support has been added
decoding docker API responses is now performed by docker-python
pulp_tag plugin has been added
inject_parent_image plugin has been added
bump_release plugin correctly increment patched release values
new filesystem-koji-task-id label is set on the OpenShift build by add_filesystem
new group_manifests post-build plugin, for creating grouping image manifests into manifest lists
new pulp_publish exit plugin, intended for orchestrator builds, to handle only the publishing task
several Pulp plugins have been adjusted to make them able to run in the orchestrator build
in addition to being a PostBuildPlugin, pulp_pull is now also an ExitPlugin
group_manifests plugin is rendered based on group_manifests configuration value
koji_import plugin uploads OpenShift logs from worker builds and orchestrator build
koji_upload plugin no longer uploads OpenShift logs
koji_upload plugin has new arguments:
- prefer_schema1_digest, to indicate when schema v1 should still be used
- platform, to indicate the platform name to use in filenames for Koji uploads
pulp_pull plugin has a new argument, expect_v2schema2, to indicate whether v2 schema 2 image manifests should be expected from Crane
communication with external HTTP services has been wrapped in a common retry approach