Break release into pieces, build images in parallel

[smarterclayton]

Includes release v3.7.0-alpha.1 tag

[openshift-merge-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: smarterclayton

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[smarterclayton]

Images pushed, going to merge after tests go green again.

[smarterclayton]

Cuts image build time from 9m to ~5m.

[openshift-ci-robot]

@smarterclayton: The following test failed, say /retest to rerun them all:

Test name	Commit	Details	Rerun command
ci/openshift-jenkins/unit	4abc0cc	link	/test unit

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