Additional CI Provider

[aepfli]

This is a draft pullrequest, it is just a small idea, i wanted to challenge first, before investing more time into this. #842

Refactoring TravisPlugin to generic Ci plugin

Moving all generics part into new CiPlugin, and implementing an interface called CiProvider, which allows for easier generation of CI specific data.

Adding GitHubActionsProvider

Allows usage of GitHub Actions, and utilizes the provided environment variables to generate necessary data.

Adding Generic Ci Provider

Which uses default fields, so other systems can be easier integrated.

[aepfli]

sidenote, this is untested, and far from final, i just wanted to show what we could theoretically do, and if this would be a suitable approach.