Remove Docker container after launch script test execution

Closes gh-5059

spring-boot-integration-tests/spring-boot-launch-script-tests/src/test/java/org/springframework/boot/launchscript/SysVinitLaunchScriptIT.java

@@ -206,6 +206,7 @@ public class SysVinitLaunchScriptIT {
 		DockerClient docker = createClient();
 		String imageId = buildImage(docker);
 		String container = createContainer(docker, imageId, script);
+		try {
 			copyFilesToContainer(docker, container, script);
 			docker.startContainerCmd(container).exec();
 			StringBuilder output = new StringBuilder();
@@ -225,6 +226,10 @@ public class SysVinitLaunchScriptIT {
 			docker.waitContainerCmd(container).exec();
 			return output.toString();
 		}
+		finally {
+			docker.removeContainerCmd(container).exec();
+		}
+	}
 
 	private DockerClient createClient() {
 		DockerClientConfig config = DockerClientConfig.createDefaultConfigBuilder()