build.gradle

buildscript {
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
    }
    dependencies {
        classpath "com.android.tools.build:gradle:2.3.3"
    }
}

allprojects {
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
    }

    // Versions-of-everything, same for all modules
    ext {
        // App version information
        majorAppVersion = 1
        minorAppVersion = 0
        patchAppVersion = 0
        buildAppVersion = 0

        // Build tools, SDKs, etc.
        buildTools = "26.0.1"
        minSdk = 16
        compileSdk = 26
        targetSdk = 26

        // Libraries versions
        supportLibraryVersion = "26.1.0"
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}