Add Docker image for CLI

[Polpetta]

This will allow jkk to be used from a Docker container

Example usages:

docker build -t test/test .
docker run --rm test/test 

It can be useful if you need to perform scheduled commands inside a Kubernetes cluster/Docker Swarm/Mesos/whatever Additionally I've set-up the automated build from the docker hub, the images will be automatically built here https://hub.docker.com/r/polpetta/jkk. The build has been configured as follows:

• master branch -> latest tag
• git tag (e.g. 1.2) -> 1.2 tag (i.e polpetta/jkk:1.2)

Note: at the moment it only supports x86

[M0Rf30]

Image built and fully working

[Polpetta]

Yep, I agree with you about JDK 13. I'll check if I'm able to upgrade the current project configuration to support it. This line in the build.gradle:

implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"

is what I think it may be the reason we're not able to switch to JDK 13, along with the compiled version:

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}