Upgrade PHPUnit to 9.0

composer.json

@@ -46,6 +46,6 @@
     },
     "require-dev": {
         "zetacomponents/unit-test": "*",
-        "phpunit/phpunit": "^7.5"
+        "phpunit/phpunit": "^9.0"
     }
 }

phpunit.xml.dist

@@ -1,14 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit bootstrap="./tests/bootstrap.php" colors="true">
-    <testsuites>
-        <testsuite name="Zeta Components Url">
-            <directory suffix="_test.php">./tests</directory>
-        </testsuite>
-    </testsuites>
-
-    <filter>
-        <whitelist>
-            <directory>./src</directory>
-        </whitelist>
-    </filter>
-</phpunit>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="./tests/bootstrap.php" colors="true" beStrictAboutTestsThatDoNotTestAnything="false" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+  <coverage>
+    <include>
+      <directory>./src</directory>
+    </include>
+  </coverage>
+  <testsuites>
+    <testsuite name="Zeta Components Url">
+      <directory suffix="_test.php">./tests</directory>
+    </testsuite>
+  </testsuites>
+</phpunit>