demo: add Azure remote demo

[lgfa29]

This PR adds cluster scaling demo on Azure using the a VMSS instance. It follows a new folder structure to better organize files per cloud provider. A following PR will adapt the AWS demo to the same structure.

It also updates the provider version constraint in the shared-nomad-jobs module so we can use depends_on between the hashistack_cluster and hashistack_jobs. Without this explicit dependency, Terraform would try to destroy the jobs after the cluster is already gone.

[lgfa29]

@jrasell any ideas on how to make Terraform destroy the jobs first? As it is, Terraform will destroy the VMs first and then try to to destroy the jobs, but it will timeout.

I tried the new depends_on for modules, but Terraform was not too happy about it.

[jrasell]

@lgfa29 I would expect the fact the jobs module has a requirement on an output of the cluster module to create the correct dependancy chain. Failing that and providing we use TF 0.13, again I would expect it to create the correct dependancy chain between the two modules. Lets look at this online later, hopefully we can figure out a nice solution other than having to do targeted destroys.

[cgbaker]

💯 🏆 🥇