molecule scenario to test upgrading from releases

Provide a separate scenario to install the last release, then update to
the current one.
Also includes improved deployment verification (check if uploading a
.txt through the API works).

ansible/molecule/fresh/molecule.yml

@@ -0,0 +1,35 @@
+---
+dependency:
+  name: galaxy
+driver:
+  name: docker
+platforms:
+  - name: ubuntu_focal
+    image: jrei/systemd-ubuntu:20.04
+    privileged: true
+    volumes:
+      - /sys/fs/cgroup:/sys/fs/cgroup:ro
+    tmpfs:
+      - /tmp
+      - /run
+      - /run/lock
+    override_command: False
+  # ubuntu 18.04 bionic works except that
+  #   the default redis configuration expects IPv6 which is not enabled in docker by default
+  #   the default Python environment is configured for ASCII instead of UTF-8
+  # ubuntu 16.04 xenial only has Python 3.5 which is EOL and breaks multiple dependencies
+  - name: debian_buster
+    image: jrei/systemd-debian:10
+    privileged: true
+    volumes:
+      - /sys/fs/cgroup:/sys/fs/cgroup:ro
+    tmpfs:
+      - /tmp
+      - /run
+      - /run/lock
+    override_command: False
+  # debian 9 stretch only has Python 3.5 which is EOL and breaks multiple dependencies
+provisioner:
+  name: ansible
+verifier:
+  name: ansible