Remove deprecated test of internal attributes via assertAttributeEquals in constructor tests

I removed the tests completely because they just test that the constructor assigns the values to the internal properties. Nothing that should be cared about from the outside.

See https://github.com/sebastianbergmann/phpunit/issues/3339#issuecomment-428843322



It is seen as bad practice to test internal stuff of objects instead of the actual input and output of mathod calls.

Signed-off-by: Morris Jobke <hey@morrisjobke.de>