Feature request: Approve promotions

[dpo...@intotosystems.com]

Hey guys,

Love this plugin.  Thanks for the hard work on it.

A feature request:  My pipeline relies on promotions using the "promoted builds" plugin.  Some of these promotions are manually-triggered, such as "promote to QA".

You already do a great job of showing promotions in the pipeline, but it would be great if you could also:

 - (optionally) Show available promotions that have not triggered yet

 - (optionally) Allow manual approval of promotions within the pipeline view

Thanks!

David