RFE: Azure provider

[pvoborni]

This is a placeholder ticket for Azure provider. Before jumping on it, it should serve for gathering use cases to figure out what to automate in Mrack and what to expect to be done outside of Mrack.

E.g. here is a reference example (in Ansible) what is needed to run VMs on Azure: https://github.com/Duffney/manage-azure-with-ansible-20-mins -In general, I'd expect it will be similar to OpenStack or AWS providers.