[ticket/13325] Update / Fix composer.lock hash.

PHPBB3-13325
[ticket/13325] Remove whitespace at end of line.

PHPBB3-13325
[ticket/13325] Make installing composer dependencies in tests folder optional.

Make phpbb_ui_test_case available unconditionally. Nothing depends on 5.3.19
here. Remove __init__ include. Composer classmap autoloading ensures classes
can be loaded.

PHPBB3-13325
Merge pull request #3141 from bantu/ticket/13325

[ticket/13325] Make installing composer dependencies in tests folder optional.