Ensure the boussole venv dir exists.

ansible/roles/boussole/tasks/main.yml

@@ -1,4 +1,9 @@
 ---
+- name: Ensure boussole venv directory exists
+  file:
+    path: "{{ boussole_venv_dir }}"
+    state: "directory"
+
 - name: Create boussole requirements.txt file
   copy:
     src: "requirements.txt"