Upgrade to PHPUnit 9

Author: rlanvin

README.md

@@ -32,7 +32,7 @@ Complete documentation and more examples are available in [the wiki](https://git
 
 ## Requirements
 
-- PHP >= 5.6
+- PHP >= 7.3
 - [intl extension](http://php.net/manual/en/book.intl.php) is recommended for `humanReadable()` but not strictly required
 
 ## Installation

composer.json

@@ -22,7 +22,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^8.0",
+        "phpunit/phpunit": "^9.0",
         "phpmd/phpmd" : "@stable"
     }
 }

tests/RRuleTest.php

@@ -2269,8 +2269,12 @@ public function quirkyRfcStrings()
 	 */
 	public function testQuirkyRfcStringsParserNotice($str,$occurrences)
 	{
-		$this->expectException(\PHPUnit\Framework\Error\Notice::class);
-		$rule = new RRule($str);
+		try {
+			$rule = new RRule($str);
+			$this->fail("Expected an notice, didn't get one");
+		} catch (\PHPUnit\Framework\Error\Notice $e) {
+			$this->assertStringContainsString("This string is not compliant with the RFC (DTSTART cannot be part of RRULE).", $e->getMessage());
+		}
 	}
 
 	/**

tests/RSetTest.php

@@ -858,9 +858,12 @@ public function quirkyRfcStrings()
 	 */
 	public function testParseQuirkyRfcStringNotice($string, $occurrences)
 	{
-		$this->expectException(\PHPUnit\Framework\Error\Notice::class);
-
-		$object = new RSet($string);
+		try {
+			$object = new RSet($string);
+			$this->fail("Expected an notice, didn't get one");
+		} catch (\PHPUnit\Framework\Error\Notice $e) {
+			$this->assertStringContainsString("This string is not compliant with the RFC (DTSTART cannot be part of RRULE).", $e->getMessage());
+		}
 	}
 
 	/**