add lewis as hypervisor

change borg notification urls

ansible/inventory/host_vars/lewis/apt.yml

@@ -0,0 +1,5 @@
+apt_install_packages:
+  - qemu-kvm
+  - libvirt-daemon-system
+  - sudo
+  - bridge-utils

ansible/inventory/host_vars/lewis/ssh_certificates.yml

@@ -0,0 +1,12 @@
+deploy_ssh_certificates:
+  - name: ssh_user_ed25519_key
+    type: user
+    key_type: ed25519
+    signing_key: hyp_user
+    host: lewis.hyp
+    principals: hypervisor
+  - name: ssh_host_ed25519_key
+    type: host
+    key_type: ed25519
+    signing_key: hyp_host
+    host: lewis.hyp