test: phpunit package name changed with version bump

Makefile

@@ -28,7 +28,7 @@
 all:
 	@cat ${.CURDIR}/README.md | ${PAGER}
 
-WANTS=		git pear-PHP_CodeSniffer phpunit
+WANTS=		git pear-PHP_CodeSniffer phpunit6
 
 .for WANT in ${WANTS}
 want-${WANT}: force
@@ -306,7 +306,7 @@ style: want-pear-PHP_CodeSniffer
 style-fix: want-pear-PHP_CodeSniffer
 	phpcbf --standard=ruleset.xml ${.CURDIR}/src/opnsense || true
 
-test: want-phpunit
+test: want-phpunit6
 	@cd ${.CURDIR}/src/opnsense/mvc/tests && \
 	    phpunit --configuration PHPunit.xml
 

src/opnsense/mvc/tests/app/models/OPNsense/Base/BaseModelTest.php

 <?php
+
 /**
  *    Copyright (C) 2016 Deciso B.V.
- *
  *    All rights reserved.
  *
  *    Redistribution and use in source and binary forms, with or without
@@ -24,7 +24,6 @@
  *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  *    POSSIBILITY OF SUCH DAMAGE.
- *
  */
 
 namespace tests\OPNsense\Base;
@@ -33,7 +32,7 @@ use \OPNsense\Core\Config;
 
 require_once 'BaseModel/TestModel.php';
 
-class BaseModelTest extends \PHPUnit_Framework_TestCase
+class BaseModelTest extends \PHPUnit\Framework\TestCase
 {
     private static $model = null;
 

src/opnsense/mvc/tests/app/models/OPNsense/Base/FieldTypes/Field_Framework_TestCase.php

 <?php
+
 /**
  *    Copyright (C) 2016 Deciso B.V.
- *
  *    All rights reserved.
  *
  *    Redistribution and use in source and binary forms, with or without
@@ -24,15 +24,15 @@
  *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  *    POSSIBILITY OF SUCH DAMAGE.
- *
  */
+
 namespace tests\OPNsense\Base\FieldTypes;
 
 /**
  * Class Field_Framework_TestCase
  * @package tests\OPNsense\Base\FieldTypes
  */
-class Field_Framework_TestCase extends \PHPUnit_Framework_TestCase
+class Field_Framework_TestCase extends \PHPUnit\Framework\TestCase
 {
     /**
      * Validate and throw exception