Often, new base images are released to the RHCC, and where the sync jobs are able to push commits into the midstream CRW GH repos and the downtream pkgs.devel repos, we can't push changes directly into eclipse/che-* repos directly w/o a PR review (even for trivial changes like this as generated by updateBaseImages.sh:

-FROM devtools/go-toolset-rhel7:1.12.8-12  as builder
+FROM devtools/go-toolset-rhel7:1.12.8-20  as builder

and

-FROM ubi8-minimal:8.1-279
+FROM ubi8-minimal:8.1-328

So in support of being able to generate PRs, I'd like to:

• install `hub` on the rhel7 Jenkins nodes: https://gitlab.cee.redhat.com/codeready-workspaces/cloud-slaves/merge_requests/14 DONE
• get permission to use devstudio-release or che-bot to create PRs against eclipse/che-* and che-dockerfiles/* repos (in progress)
• rewrite updateBaseImages.sh to be able to generate PRs against personal forks and submit them for review (in progress); alternatively, existing script can simply be run with the updateBaseImages.sh --nocommit flag, then Jenkinsfile scripts would call out to new generatePREmail.sh script to generate a PR email for the proposed change to the repo.

New generatePREmail.sh script should be located in https://github.com/eclipse/che/tree/master/.ci for central convenience and reuse.