Android无法解析配置的所有依赖关系＆＃39;类路径＆＃39;

Question

这就像我第一次使用Android Studio，当我尝试运行应用程序时它向我显示以下错误：

Error:A problem occurred configuring root project 'PickApp'.
> Could not resolve all dependencies for configuration ':classpath'.
   > Could not resolve com.android.tools.build:gradle:0.12.+.
     Required by:
         :PickApp:unspecified
      > Failed to list versions for com.android.tools.build:gradle.
         > Could not list versions using M2 pattern 'http://jcenter.bintray.com/[organisation]/[module]/[revision]/[artifact]-[revision](-[classifier]).[ext]'.
            > Could not GET 'http://jcenter.bintray.com/com/android/tools/build/gradle/'.
               > jcenter.bintray.com

Build.grandle：

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.12.+'

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

allprojects {
    repositories {
        jcenter()
    }
}