Fixed Declaration of Kir\MySQL\Common\DBTestCase::setUp() must be compatible with PHPUnit\Framework\TestCase::setUp(): void

Author: rkrx

.travis.yml

@@ -18,7 +18,7 @@ services:
 install:
   - |
       # Install PHPUnit v9 on PHP 8
-      if dpkg --compare-versions "${TRAVIS_PHP_VERSION}" ge 8.0; then
+      if [ "${TRAVIS_PHP_VERSION}" == nightly ] || [ dpkg --compare-versions "${TRAVIS_PHP_VERSION}" ge 8.0 ]; then
           travis_retry composer require --no-interaction --prefer-dist --dev --ignore-platform-reqs "phpunit/phpunit" 9.*
       # Enable test on PHP 7.1+
       else

tests/Common/DBTestCase.php

@@ -29,13 +29,13 @@ protected function use(Closure $fn) {
 		TestDB::use($fn);
 	}
 
-	protected function setUp() {
+	protected function setUp(): void {
 		parent::setUp();
 		$this->db = new TestDB();
 		$this->db->exec('USE travis_test');
 	}
 
-	protected function tearDown() {
+	protected function tearDown(): void {
 		parent::tearDown();
 		$this->db->close();
 		$this->db = null;