build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    ext.kotlin_version = '1.2.30'
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}
apply plugin: 'kotlin'

allprojects {
    repositories {
        google()
        jcenter()
    }
}

clean {
    delete rootProject.buildDir
}
repositories {
    mavenCentral()
}
dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
}
compileKotlin {
    kotlinOptions {
        jvmTarget = "1.8"
    }
}
compileTestKotlin {
    kotlinOptions {
        jvmTarget = "1.8"
    }
}