title: Use dynamic port from Spring Boot in Geb configuration
body: <p>Spring Boot's test framework has an option to select a random port for a test run with <code>'server.port:0'</code>. <a href="http://docs.spring.io/spring-boot/docs/current/reference/html/howto-embedded-servlet-containers.html#howto-discover-the-http-port-at-runtime" rel="nofollow">The documentation suggests grabbing the port as a Spring <code>@Value</code></a>, but I'm wanting to use it to set the <code>baseUrl</code> in my <code>GebConfig.groovy</code>. Is there a way to access the dynamic port number from within the ConfigSlurper?</p>