feat(aws-codepipeline): New Pipeline#addStage convenience method.

Added to make creating Stage objects a little more concise.

packages/@aws-cdk/aws-codepipeline/README.md

@@ -16,6 +16,13 @@ const sourceStage = new Stage(this, 'Source', {
 });
 ```
 
+There's also a utility method on the `Pipeline` class that can be used for this purpose:
+
+```ts
+// equivalent to the code above:
+const sourceStage = pipeline.addStage('Source');
+```
+
 Add an Action to a Stage:
 
 ```ts

packages/@aws-cdk/aws-codepipeline/lib/pipeline.ts

@@ -121,6 +121,19 @@ export class Pipeline extends cdk.Construct implements events.IEventRuleTarget {
  }));
  }
 
+ /**
+ * Convenience method for creating a new {@link Stage},
+ * and adding it to this Pipeline.
+ *
+ * @param name the name of the newly created Stage
+ * @returns the newly created Stage
+ */
+ public addStage(name: string): Stage {
+ return new Stage(this, name, {
+ pipeline: this,
+ });
+ }
+
  /**
  * Adds a statement to the pipeline role.
  */

packages/@aws-cdk/aws-codepipeline/test/integ.pipeline-code-commit.ts

@@ -10,7 +10,7 @@ const repo = new codecommit.Repository(stack, 'MyRepo', { repositoryName: 'my-re
 
 const pipeline = new codepipeline.Pipeline(stack, 'Pipeline');
 
-const sourceStage = new codepipeline.Stage(pipeline, 'source', { pipeline });
+const sourceStage = pipeline.addStage('source');
 repo.addToPipeline(sourceStage, 'source', {
  artifactName: 'SourceArtifact',
 });