Add external providers

[restanrm]

I would like to propose to add 2 providers in this PullRequest. If you prefer to have a PR per provider I could do it as well.

The providers added are Scaleway and OVH

[danielfoehrKn]

Holy cow, thank you very much for that contribution (in my review, I did not see anything wrong with it code-wise). I appreciate you very much. I apologize for the long delay.

As I don't have Scaleway or OVH accounts, I will have to rely on the community to try it out. From what I see from the code it looks great.

[danielfoehrKn]

Btw, I would appreciate it if you would add a small documentation for the Scaleway provider like you did for OVH. This way people can use the provider more easily. No hurry though.

[restanrm]

Btw, I would appreciate it if you would add a small documentation for the Scaleway provider like you did for OVH. This way people can use the provider more easily. No hurry though.

Thank you for you review. I wanted to add it to this PR but could not find time to do it and then later forgot about it. I will add the documentation as soon as possible !