Sample separate dependency file

dependencies.gradle

ext {
    kotlinVersion = '1.3.11'
    appCompatVersion = "28.0.0"

    junit4Version = "4.12"

    libraries = [          
            kotlinStdLib         : "org.jetbrains.kotlin:kotlin-stdlib-jdk7:" + kotlinVersion,
            constraintLayout     : "com.android.support.constraint:constraint-layout:" + constraintLayoutVersion
    ]
    
    testLibraries = [
            junit4   : "junit:junit:" + junit4Version
    ]

    androidTestLibraries = [
            testRunner: "com.android.support.test:runner:" + testRunnerVersion
    ]
}