build.gradle

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

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

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

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

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

// define versions.
ext {
    // app version.
    versionCode = 1
    versionName = '0.0.1'

    // tools and sdk.
    minSdkVersion = 19
    targetSdkVersion = 27
    compileSdkVersion = 27
    buildToolsVersion = '27.0.0'

    // app dependencies.
    junitVersion = '4.12'
    espressoVersion = '2.2.2'
    supportLibraryVersion = '27.0.0'
    retrofitVersion = '2.3.0'
    okhttpVersion = '3.9.0'
    butterknifeVersion = '8.8.1'
    glideVersion = '3.7.0'
}