revert handling

[travi]

tl;dr: add an integration test for the revert behavior when a change is committed and reverted in the scope of the same release

the recent changes with the conventional-changelog dependencies changed the order that the commits are processed. we have tests in the related plugins to cover the expected revert behavior, but this change resulted in a need to change the test data. that sent me on an investigation to confirm that the real commit data would actually match the new order of the test data and i failed to find a higher level test that covered the scope of reading the commits and handling the revert behavior.

i ended up doing some manual tests, as mentioned in #2934 (comment). i dont want getting this test added to further delay getting #2934 released, so capturing this for a follow up.

we should add an integration test in this project for this case since it would have a large enough scope to cover all of the pieces involved. in addition, i think there is an opportunity to extract some helper functions to reduce some duplication in the integration test file and make the tests easier to read and follow.