minor #16568 Update testing.rst (xElysioN)

This PR was merged into the 4.4 branch.

Discussion
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Update testing.rst

Fix typo in Unit Test block

https://symfony.com/doc/4.4/testing.html#unit-tests

Commits
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b73bfd1 Update testing.rst

Author: javiereguiluz

testing.rst

@@ -99,7 +99,7 @@ You can run tests using the ``./vendor/bin/phpunit`` command:
 .. tip::
 
     In large test suites, it can make sense to create subdirectories for
-    each type of tests (e.g. ``tests/Unit/`` and ``test/Functional/``).
+    each type of tests (e.g. ``tests/Unit/`` and ``tests/Functional/``).
 
 .. _integration-tests: