PikmailApiBuild.gradle

...
mainClassName = 'org.jetbrains.ktor.netty.DevelopmentHost'

kotlin {
    experimental {
        coroutines "enable"
    }
}

...

dependencies {
    ...
    compile "org.jetbrains.ktor:ktor-netty:$ktor_version"
    compile "com.github.epool:pikmail:1.0.1"
    compile "org.jetbrains.kotlinx:kotlinx-coroutines-rx2:0.19.3"
    ...
}

...

jar {
    manifest {
        attributes(
                'Main-Class': 'com.nearsoft.pikmail.api.Main'
        )
    }
    from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
}

task stage(type: Copy, dependsOn: [clean, build]) {
    from jar.archivePath
    into project.rootDir
    rename {
        'pikmail-api.jar'
    }
}
stage.mustRunAfter(clean)
...