Travis CI生成失败:无法解析网址:org.jetbrains.kotlin:科特林·格拉德尔-插件:1.2.50[副本]

我使用Gradle构建我的Kotlin项目,并使用travisci进行持续集成。在合并上一个pull请求之后,我发现Travis CI构建失败了。在日志中我看到下一个:

FAILURE: Build failed with an exception.

> Could not resolve all files for configuration ':classpath'.
   > Could not resolve org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.50.
     Required by:
         project :
      > Could not resolve org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.50.
         > Could not get resource 'https://repo1.maven.org/maven2/org/jetbrains/kotlin/kotlin-gradle-plugin/1.2.50/kotlin-gradle-plugin-1.2.50.pom'.
            > Could not GET 'https://repo1.maven.org/maven2/org/jetbrains/kotlin/kotlin-gradle-plugin/1.2.50/kotlin-gradle-plugin-1.2.50.pom'. Received status code 403 from server: Forbidden

据我所知,Gradle无法获得Kotlin插件,但当我尝试在本地构建项目时,一切都很好(实际上,我没有更改任何与构建过程相关的内容)。我还检查了上述文件的可用性-“kotlin-gradle-plugin-1.2.50.pom”,我可以在浏览器中打开它。这是我的构建.gradle配置:

buildscript {
    ext.kotlin_version = '1.2.50'

    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

version '1.' +  System.getProperty("buildNumber")

apply plugin: 'kotlin'

repositories {
    mavenCentral()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
}

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

问题的原因应该是什么?我如何解决?