chore: Updated phpunit config

Author: alexsoft

phpunit.xml.dist

@@ -11,14 +11,16 @@
          stopOnFailure="false">
     <testsuites>
         <testsuite name="Pushbullet Notification Channel Test Suite">
-            <directory>tests</directory>
+            <directory suffix="Test.php">tests</directory>
         </testsuite>
     </testsuites>
+
     <filter>
-        <whitelist>
-            <directory suffix=".php">src/</directory>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
         </whitelist>
     </filter>
+
     <logging>
         <log type="tap" target="build/report.tap"/>
         <log type="junit" target="build/report.junit.xml"/>