AS 相关技巧

使用 阿里云 aliyun 的 maven 去下载依赖：

buildscript {
    repositories {
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
        maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
        mavenCentral()
        google()
    }
}
repositories {
    maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
    maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    mavenCentral()
    google()
}