build.gradle

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

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
    // WARNING: don't use 'project.ext' because IDE 'Cannot infer argument type'
    // https://stackoverflow.com/questions/20404476/how-to-define-common-android-properties-for-all-modules-using-gradle
    // Gradle constants example: https://github.com/google/ExoPlayer
    ext {
        compileSdkVersion = 27
        buildToolsVersion = "27.0.3"
        minSdkVersion = 14
        targetSdkVersion = 27
        appCompatVersion = 'com.android.support:appcompat-v7:27.+'
        espressoCoreVersion = 'com.android.support.test.espresso:espresso-core:2.2.2'
        junitVersion = 'junit:junit:4.12'
        supportVersion = 'com.android.support:support-v4:27.+'
        robolectricVersion = 'org.robolectric:robolectric:3.5.1'
        crashlyticsVersion = 'com.crashlytics.sdk.android:crashlytics:2.8.0@aar'
    }
}

allprojects {
    repositories {
        jcenter()
        // com.android.support libs
        maven { url 'https://maven.google.com' }
    }
}

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