- prep changelog for future changes
- composer changes from re-running composer on the repo, testing deps
- change to phpunit coverage make target, required with newer releases
having had to re-do all of these steps on a new environment, I noticed
some inconsistencies and updated the doc:
- moved unit testing doc into common doc folder, so it is easier to find
- removed no longer supported Janitor reference
- removed note regarding generated test duration, current version takes
less than a minute
- addressed each function removal & phpunit deprecations