title: "Cannot invoke method repositories() on null object" when running gradle build
body: <p>I was following the <a href="https://projects.spring.io/spring-shell/#quick-start" rel="nofollow noreferrer">quickstart guide for spring-shell</a> when I hit:</p>
  
  <pre><code>&gt; Cannot invoke method repositories() on null object
  </code></pre>
  
  <p>My <code>build.gradle</code> copied their instructions exactly:</p>
  
  <pre><code>dependencies {
      compile 'org.springframework.shell:spring-shell-starter:2.0.1.BUILD-SNAPSHOT'
  }repositories {
      maven {
          url 'https://repo.spring.io/libs-snapshot'
      }
  }
  </code></pre>
  
  <p>How do I get my project to build?</p>