Dependencies and jar-task in build.gradle for AWS Lambda function on Java for Amazon Alexa Skill

build.gradle

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
    compile group: 'com.amazon.alexa', name: 'ask-sdk', version:'2.17.2'
    compile group: 'com.amazonaws', name: 'aws-lambda-java-log4j2', version:'1.1.0'
}
jar {
    from {
        configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
    }
}