Use Ansible instead of Bash for provisioning

The deployment is not quite working, and I'm unable to test right now:
DigitalOcean is returning 503 for my requests.

As of this commit, I can run =ansible-playbook provider.yml= more than once and
it will actually be idempotent.

Notes:
- SSH fingerprint are now taken from the public key file instead of manually
supplying it in the terraform template using the =digitalocean_ssh_key=
resource;
- use Ansible instead of ad-hoc Bash scripts for provisioning the Droplets
created by Terraform;
- use the =filename.env.extension= to create the concrete files in CI;
- use the =user_data= to add the know SSH key pair to the newly created Droplet;
- add =rotate-ssh-keys.sh= utils;

1 files changed, 2 insertions, 0 deletions

diff --git a/hosts.env b/hosts.env
new file mode 100644
index 0000000..62fa199
--- /dev/null
+++ b/hosts.env
@@ -0,0 +1,2 @@
+[vps]
+$TLD