Run Unit Tests against PHP 7.4

Bump PHPUnit version and fix unit test

  - Globals are handled differently and are persistent through tests
  - Tests without assertions are marked as risky: some of them are just
meant to check that no error is raised.

1 files changed, 1 insertions, 2 deletions

diff --git a/tests/PluginManagerTest.php b/tests/PluginManagerTest.php
index 71761ac1..195d959c 100644
--- a/tests/PluginManagerTest.php
+++ b/tests/PluginManagerTest.php
@@ -58,13 +58,12 @@ class PluginManagerTest extends \PHPUnit\Framework\TestCase
 
     /**
      * Test missing plugin loading.
-     *
-     * @return void
      */
     public function testPluginNotFound()
     {
         $this->pluginManager->load(array());
         $this->pluginManager->load(array('nope', 'renope'));
+        $this->addToAssertionCount(1);
     }
 
     /**