This introduces a new rbintegrations.baseci module, containing a

BaseCIIntegration class. This class is responsible for listening to

publish and manual run requests, handling configuration queries, and

providing standard management of status updates.
There are new helpers for updating status updates with arbitrary fields,

or putting them into specific (standardized) modes. These are smart in

that they'll only make changes to status updates for fields that are

given new values.
Subclasses no longer need to implement separate code paths for publish

and manual run. Instead, they just implement an optional

prepare_build() method to filter configurations or supply state for

builds, and start_build() for actually performing the build.
Build state generation and validation is taken care of in the base

class, and errors on status updates are automatically set based on

whether start_build() raises a CIBuildError or a plain exception.
This will soon be followed up by a change to make use of new

StatusUpdate methods for status changes, and to correctly handle

manual run requests for the right configuration. Both of those will

be available in Review Board 5.0.3.

Unit tests pass on all supported versions of Python.
This will be pending a test in production by a customer.