#131 changed the behaviour of deployment to be single-stage (except when publishing to prod).

This means publishing to "ops" will target "ops" only (it used to be dev + ops).

Some provisioned plugins (e.g.: logs-drilldown) want to run CD in dev + ops. This is not possible anymore after merging #131. We should keep the default behavior as-is, but allow publishing to dev + ops if the plugin specifies so.

E.g.:

environment: dev,ops