maint - update Rakefile to use non-weird test task

The old test task required all of the development dependencies to be available
for all targets.
Reset the version to 4.3.0

We want the Rakefile update from 50a9fa4893519 for 4.3.0

This reverts commit 20c01ae3bf20daa8128e0f7bda17235cccffe754.