Merge pull request #2418 from rodrigoprimo/fix-typo-in-contributing-md

Fix the test case file path used in a CONTRIBUTING.md example

Author: dingo-d

.github/CONTRIBUTING.md

@@ -138,7 +138,7 @@ Also note the class name convention. The method `getErrorList()` MUST return an
 If you run the following from the root directory of your WordPressCS clone:
 
 ```sh
-$ "vendor/bin/phpcs" --standard=Wordpress -s ./Tests/PHP/POSIXFunctionsUnitTest.inc --sniffs=WordPress.PHP.POSIXFunctions
+$ "vendor/bin/phpcs" --standard=Wordpress -s ./WordPress/Tests/PHP/POSIXFunctionsUnitTest.inc --sniffs=WordPress.PHP.POSIXFunctions
 ...
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 FOUND 7 ERRORS AFFECTING 7 LINES