update code coverage settings

Author: Ryuta Hamasaki

phpunit.xml

@@ -14,8 +14,14 @@
     </testsuites>
     <coverage processUncoveredFiles="true">
         <include>
-            <directory suffix=".php">./app</directory>
+            <directory suffix=".php">./src</directory>
         </include>
+        <exclude>
+            <directory suffix="Test.php">./src/**/Tests/*</directory>
+        </exclude>
+        <report>
+            <clover outputFile="coverage/clover.xml"/>
+        </report>
     </coverage>
     <php>
         <server name="APP_ENV" value="testing"/>