Rely on the official ENV var for Docker repo

* Remove obsolete `TestUtils.dockerRegistryFromEnv()`
* Upgrade to Spring GraphQL `1.0.0`

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/mysql/MySqlContainerTest.java

@@ -34,11 +34,7 @@ import org.springframework.integration.test.util.TestUtils;
 public interface MySqlContainerTest {
 
 	@Container
-	MySQLContainer<?> MY_SQL_CONTAINER =
-			new MySQLContainer<>(
-					DockerImageName.parse(TestUtils.dockerRegistryFromEnv() + "mysql")
-							.asCompatibleSubstituteFor("mysql"))
-					.withReuse(true);
+	MySQLContainer<?> MY_SQL_CONTAINER = new MySQLContainer<>("mysql").withReuse(true);
 
 
 	static String getDriverClassName() {