Enable and disable pipelines per environment

[philipp94831]

Some pipelines should only be deployed to specific environments. In order to define that in a file instead of having the user know which pipelines to deploy, it should be configurable in config.yaml.

Consider we have the following pipelines:

• foo/pipeline-1
• foo/pipeline-2
• bar/pipeline-1
• bar/pipeline-2
• baz/pipeline-1
• baz/pipeline-2

Proposal is to have two modes:

enabled_pipelines:
 - foo/pipeline-1
 - bar

This enables all pipelines in foo/pipeline-1 and in bar. All other pipelines are disabled. Enabled pipelines are:

• foo/pipeline-1
• bar/pipeline-1
• bar/pipeline-2

disabled_pipelines:
 - foo/pipeline-1
 - bar

This disables all pipelines in foo/pipeline-1 and in bar. All other pipelines are disabled. Enabled pipelines are:

• foo/pipeline-2
• baz/pipeline-1
• baz/pipeline-2

Depends on #153