Update phpunit.xml.dist

Author: neildaniels

phpunit.xml.dist

@@ -2,7 +2,7 @@
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" backupGlobals="false" backupStaticAttributes="false" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false" bootstrap="test/bootstrap.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
   <coverage>
     <include>
-      <directory>lib</directory>
+      <directory suffix=".php">lib</directory>
     </include>
   </coverage>
   <testsuites>