Move publishing flank-scripts from bintray to other place

[piotradamczyk5]

Author the user story for this feature

As a Developer, I want to upload flank-scripts to maven repository with direct link so I can download it when needed.

Describe the solution
Currently, we are uploading flank-scripts to bintray which will be closed at the end of April, so we should found another place to store flank-scripts binaries.

Please update also flank-scripts download task

tasks.register("download") {
    val sourceUrl = "https://dl.bintray.com/flank/maven/com/github/flank/$artifactID/$version/$artifactID-$version.jar"
    val destinationFile = Paths.get("bash", "flank-scripts.jar").toFile()
    ant.invokeMethod("get", mapOf("src" to sourceUrl, "dest" to destinationFile))
}

Requirements

1. Free
2. Easy to upload and download
3. Possibility to get a direct link to download jar

Possible solutions

• Jitpack

Describe alternatives considered
As an alternative, we could upload flank-scripts to Github packages and get a link through Github API, but it needs one additional request with parsing output

[bootstraponline]

my preference is to use the github maven repo https://github.com/features/packages

github is unlikely to go away

jitpack could disappear in the same way jcenter did

[piotradamczyk5]

@bootstraponline I see your point of view, but please notice, that flank-scripts is just used internally by our team.
What is more, we do not use it as Gradle dependency, but as a bash program, so we just need to download the right jar for it.
Github packages do not have a direct link to download jar as well as API to retrieve it, so for this particular case I think we should add it to jitpack to use it as easy as possible

EDIT:
I will publish flank-scripts to both github release and github packages