build.gradle

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

buildscript {
    repositories {
        jcenter()
        google()
    }
    
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0'

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

allprojects {
    repositories {
        mavenCentral()
        jcenter()
        google()
        maven { url "https://jitpack.io" }
        maven { url 'https://maven.google.com' }
        maven { url "https://oss.sonatype.org/content/repositories/snapshots" }
    }

    //NOTE: This is important
    rootProject.ext {
        BuildTools = "27"
        MinSdk = 15
        TargetSdk = 27
        CompileSdk = 27
    }
}

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