minor #5255 Tests: do not skip documentation test (keradus)
minor #5255 Tests: do not skip documentation test (keradus)

This PR was merged into the 2.15 branch.

Discussion
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Tests: do not skip documentation test

closes: #5209

looks like we can re-enable the docs tests after the fixes in https://github.com/FriendsOfPHP/PHP-CS-Fixer/pull/5236

related:
- #5256 => green Travis on 2.16 with test enabled
- #5257 => green Travis on master with test enabled
- #5258 => green Travis on 3.0 with test enabled

Commits
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c8a0611d2 Tests: do not skip documentation test

kubawerlos/PHP-CS-Fixer,keradus/PHP-CS-Fixer,keradus/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,gharlan/PHP-CS-Fixer