Add support to reject changes from approvals
Formally "support for negative requirements"
This change adds support to reject a change from entering a pipeline
based off any existing approvals. This is useful to stop queuing any
changes with a negative vote.
Two new options are added:
approval: - ...
To the pipelines, and:
To the triggers.
The approval format is the same for the "require approval" section.
Reject approvals could be considered a negative of the require section.