Manual Deployment via Slack / Github Deployments

Is it possible to trigger manual deployments via Slack in conjunction with Github Deploment API?

Rather than automatically deploy when a build is green, we would like to deploy manually, ideally via slack.

Are there plans to extend the CircleCI hubot to trigger deployments?

The intention of using a manual deploy is to have the ability to deploy a feature branch into an environment before it has been merged into master. So if there is a problem, when maintain the ability to quickly rollback to a known acceptable release.