阿里雲 gradle鏡像庫 解決原maven下載慢的問題

原maven經常大姨媽、下載慢，讓人很痛苦。阿里鏡像可以加速下載，gradle配置文件是從上往下查找的，需要把阿里雲放前面，這樣基本就秒下 

buildscript {
    repositories {
        maven{ url 'https://maven.aliyun.com/repository/google'}
        maven{ url 'https://maven.aliyun.com/repository/gradle-plugin'}
        maven{ url 'https://maven.aliyun.com/repository/public'}
        maven{ url 'https://maven.aliyun.com/repository/jcenter'}

        jcenter()
        google()
    }
    dependencies {
        .......
    }
}

allprojects {
    repositories {
        maven{ url 'https://maven.aliyun.com/repository/google'}
        maven{ url 'https://maven.aliyun.com/repository/gradle-plugin'}
        maven{ url 'https://maven.aliyun.com/repository/public'}
        maven{ url 'https://maven.aliyun.com/repository/jcenter'}

        jcenter()
        google()
    }
}

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