fix(@angular/cli): obey the flat option when generating modules (angular#5411)

Fixes angular#5373

Author: Brocco

packages/@angular/cli/blueprints/module/index.ts

@@ -53,6 +53,7 @@ export default Blueprint.extend({
 
     return {
       dynamicPath: this.dynamicPath.dir,
+      flat: options.flat,
       spec: options.spec,
       routing: options.routing
     };