Update launch script integration tests to work with Docker 1.12

Closes gh-6914 (I hope)

Author: wilkinsona

spring-boot-integration-tests/spring-boot-launch-script-tests/README.adoc

@@ -10,9 +10,10 @@ The setup that's required varies depending on your operating system.
 
 === Docker on OS X
 
-Docker relies on Linux kernel features so the Docker Daemon must be run inside a Linux VM.
-Following the https://docs.docker.com/engine/installation/mac/[OS X installation
-instructions] to install Docker Toolbox which uses VirtualBox to host the required VM.
+The latest version of Docker runs as a native Mac application but isn't supported by
+docker-java. This means that you should use Docker Toolbox. See the
+https://docs.docker.com/engine/installation/mac/[OS X installation instructions] for
+details.
 
 === Docker on Linux
 

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

@@ -233,7 +233,7 @@ public void onNext(Frame item) {
 
 	private DockerClient createClient() {
 		DockerClientConfig config = DockerClientConfig.createDefaultConfigBuilder()
-				.build();
+				.withVersion("1.19").build();
 		DockerClient docker = DockerClientBuilder.getInstance(config)
 				.withDockerCmdExecFactory(this.commandExecFactory).build();
 		return docker;