* Add missing preview features of Deployment and Deployment Statuses API
- Enable support for deployment status states in_progress and queued
- Add arguments production_environment and transient_environment to Repository.create_deployment()
- Add attributes production_environment and transient_environment to Deployment
- Use correct type in assertion for Deployment.payload
- Fix incorrect assertion for description in Deployment.create_status()
- Add arguments environment, environment_url, auto_inactive to Deployment.create_status()
- Add attribute environment_url to DeploymentStatus
A lot of our missing coverage is caused by not checking repr(), which is
trivial enough to test against -- do so, and also clean up existing repr
tests to look the same by calling repr(). Where it was trivial, add a
few assertions about missing attributes.
Add a new class, Deployment to describe a deployment performed utilising
GitHub. Add three methods onto Repository to list them and create them.
Fixes#1117
