Lightning should provide an acquia-pipelines.yml file that works with Acquia Cloud OOTB

[anavarre]

This is a follow-up to #94. We'd like to improve the acquia-pipelines.yml file to make it Acquia Cloud-friendly as much as possible. Even if there's code that is commented out, it'd be a great starting point for users to be able to quickly get started on Acquia Cloud.

Changes involve the following:

• Changing - lightning configure:cloud to - lightning configure:cloud $PIPELINE_CLOUD_SITE
• Adding a post-deploy step for demonstrating CDEs. Example below:

  post-deploy:
    steps:
      # Deploy the build artifact to an on-demand environment,
      # and sync the specified databases.
      - deploy:
          script:
            - pipelines-deploy
            - pipelines-sync-dbs
            # See https://docs.acquia.com/acquia-cloud/develop/pipelines/databases/