Publish fat-jar with Gradle shadow plugin

[jitpack-io]

From: https://stackoverflow.com/q/49698961/4562758

It's not immediately intuitive on how to publish a fat JAR to JitPack because the shadow docs don't have a section for JitPack and the JitPack docs don't have a section on fat jars.

All the docs say is that if you include maven-publish then they will execute the task publishToMavenLocal.

Normally a shadowJar fat jar is created via gradle shadowjar but the build command on JitPack is not configurable therefore we must modify our publishToMavenLocal to use shadowJar.

[jitpack-io]

To publish shadow jar on JitPack use:

plugins {
    id "com.github.johnrengelman.shadow" version "2.0.2"
}

apply plugin: 'java'
apply plugin: 'maven'
apply plugin: 'com.github.johnrengelman.shadow'

group = 'com.github.jitpack-io'

repositories {
  mavenCentral()
}

dependencies {
  compile 'com.google.guava:guava:18.0'
  testCompile 'junit:junit:4.12'
}

shadowJar {
    archiveName = "$baseName-$version.$extension"
}

artifacts {
    archives shadowJar
}

Example: https://github.com/jitpack-io/gradle-simple/blob/shadow/build.gradle