Revert "Composer requirement increased to 5.4.x"

This reverts commit 68f12c624513c1fbe0991287849564e455f4cf81.
Revert trait based drivers
Revert "Readme updated to indicate 5.4 requirement"

This reverts commit 566f414385c774e68e46cc0649a7786ede881d32.
Revert "Readme updated for new subclass syntax"

This reverts commit 7da421f13ce49d07a8ed6200abb0f8bdfc835928.
More trait reverts
Added code coverage reporting to phpunit.xml. Reports are ignored by git