adding individual phpunit.xml and bootstrap.php

apps/dav/tests/unit/bootstrap.php

+<?php
+
+define('PHPUNIT_RUN', 1);
+
+require_once __DIR__.'/../../../../lib/base.php';
+
+if(!class_exists('PHPUnit_Framework_TestCase')) {
+	require_once('PHPUnit/Autoload.php');
+}
+
+\OC_App::loadApp('dav');
+
+OC_Hook::clear();

apps/dav/tests/unit/phpunit.xml

+<?xml version="1.0" encoding="utf-8" ?>
+<phpunit bootstrap="bootstrap.php"
+		 verbose="true"
+		 timeoutForSmallTests="900"
+		 timeoutForMediumTests="900"
+		 timeoutForLargeTests="900"
+		>
+	<testsuite name='unit'>
+		<directory suffix='test.php'>.</directory>
+	</testsuite>
+	<!-- filters for code coverage -->
+	<filter>
+		<whitelist>
+			<directory suffix=".php">../../dav</directory>
+			<exclude>
+				<directory suffix=".php">../../dav/tests</directory>
+			</exclude>
+		</whitelist>
+	</filter>
+	<logging>
+		<!-- and this is where your report will be written -->
+		<log type="coverage-clover" target="./clover.xml"/>
+	</logging>
+</phpunit>
+