SingleLineAfterImportsFixer - fix for line after import (and before another import) already added using CRLF

[kubawerlos]

The original test for CRLF was run in tests for PHP 7.0, so in this PR it's moved to test which runs on all PHP versions.

Follow up to #5029

[SpacePossum]

Maybe we can add a test step to Travis to run the fixer on its own code base with line break setting to \r\n and than run it again with \n and test the code is still the same ;)

[kubawerlos]

@SpacePossum I was about adding a test in AutoReview when we test code samples that would take each code sample after fixing, run \n -> \r\n\ replace and check if nothing is changed. Of course, there would be some exceptions like line_ending fixer. WDYT?

[SpacePossum]

sounds great to me! we could do the same with the indenting spaces vs. tabs, however I've no idea how hard it would be to build so don't sink to much effort in it :)

[kubawerlos]

@SpacePossum POC of the AutoReview changes: #5039

[SpacePossum]

Thank you @kubawerlos.