All the setup/teardown/pre/post/conditions template methods
now are required to return void. This was warned with phpunit 7
and now is enforced.
At the same time, fix a few wrong function names,
provider data and param types, return statements...
1. getMock()
2. setExpectedException()
3. checkForUnintentionallyCoveredCode renamed to beStrictAboutCoversAnnotation
4. beStrictAboutTestSize renamed to enforceTimeLimit
5. UnitTestCase class is now fully removed.