Fix Gitlab CI, lint, start updating to molecule 3

I couldn't get molecule to actually work again - appears to be some issue with ansible+systemd+docker.

This also fixes a security issue: The django secret key was previously installed as 644 (world-readable).

tasks/funkwhale.yml

@@ -20,7 +20,7 @@
     owner: "{{ funkwhale_username }}"
     group: "{{ funkwhale_username }}"
     state: directory
-    mode: '750'
+    mode: '755'
   with_items:
     - "{{ funkwhale_install_path }}"
     - "{{ funkwhale_media_path }}"