JUnit "5 / Jupiter / Platform" snapshot console launcher task

No need for the download task and custom config, you can just do

dependencies {
    testRuntime 'org.junit.platform:junit-platform-console:1.0.0-SNAPSHOT'
    testRuntime 'org.junit.jupiter:junit-jupiter-engine:5.0.0-SNAPSHOT'
}

...

classpath = project.sourceSets.test.runtimeClasspath