add changes for vampir mitgliederdatenbank 2.0

uwsgi-python/tasks/apps/vampir-mitglieder.yml

+---
+
+- name: ensure we have a folder for invoices
+  file:
+    path: "{{ app_path }}/rechnungen"
+    state: directory
+    owner: "{{ app_user }}"
+    group: "{{ app_group }}"
+    mode: '0750'