title: Junit 5 gradle plugin not found
body: <p>Try to use junit 5 with gradle:</p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath 'org.junit.platform:junit-platform-gradle-plugin:1.0.0'
      }
  }
  
  apply plugin: 'java-library'
  apply plugin: 'org.junit.platform.gradle.plugin'
  ...
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>Plugin with id 'org.junit.platform.gradle.plugin' not found.
  </code></pre>
  
  <p>Gradle version 4.0. What is wrong?</p>