Create Deployment

Deployments offer a few configurable parameters with certain defaults. The `ref` parameter can be any named branch, tag, or SHA. At GitHub Enterprise Server we often deploy branches and verify them before we merge a pull request. The `environment` parameter allows deployments to be issued to different runtime environments. Teams often have multiple environments for verifying their applications, such as `production`, `staging`, and `qa`. This parameter makes it easier to track which environm...