Setup staging system

[rickr]

We should have a staging environment to test changes.

Possible ideas:

Github bot to manually deploy a PR to staging
Subdomain for each PR number

Things to remember:
We'll need a way to make sure that staging reverts back to master after each PR is merged

[desnudopenguino]

I'm sure you could automate a deployment somehow, or at least throw together a Terraform plan or Ansible playbook to deploy a staging environment. Then when you are done you can simply terraform destroy and it is gone.