title: Generating Components without *.spec.ts in Angular 6
body: <p>In previous version, spec.ts can be disabled with .angular-cli.json as below.
  Is there any way to do it with angular.json in version 6.0.0?</p>
  
  <pre><code>"defaults": {
      "component": { 
          "spec": false 
      },
      "service": { 
          "spec": false 
      },
      ...
  }
  </code></pre>