Mounting data to data folder

[Vayel]

As discussed with @julien-bayle, I edited the docker-compose.yml to mount services data to local folders in data :

    volumes:
      - ./data/combo:/var/lib/combo/tenants
      - ./data/hosts:/etc/hosts

But when I start the combo service, I get the error below:

components    | [....] Starting Portal Management System : combo[info] Applying migrations (migrate_schemas)...
components    | [info] done.
components    | [info] Collect static files (collectstatic)...
components    | Copying '/usr/lib/python3/dist-packages/xstatic/pkg/opensans/data/fonts/SemiboldItalic/OpenSans-SemiboldItalic.svg'
components    | Traceback (most recent call last):
components    |   File "/usr/lib/combo/manage.py", line 10, in <module>
components    |     execute_from_command_line(sys.argv)
components    |   File "/usr/lib/python3/dist-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
components    |     utility.execute()
components    |   File "/usr/lib/python3/dist-packages/django/core/management/__init__.py", line 356, in execute
components    |     self.fetch_command(subcommand).run_from_argv(self.argv)
components    |   File "/usr/lib/python3/dist-packages/django/core/management/base.py", line 283, in run_from_argv
components    |     self.execute(*args, **cmd_options)
components    |   File "/usr/lib/python3/dist-packages/django/core/management/base.py", line 330, in execute
components    |     output = self.handle(*args, **options)
components    |   File "/usr/lib/python3/dist-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 199, in handle
components    |     collected = self.collect()
components    |   File "/usr/lib/python3/dist-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 124, in collect
components    |     handler(path, prefixed_path, storage)
components    |   File "/usr/lib/python3/dist-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 364, in copy_file
components    |     self.storage.save(prefixed_path, source_file)
components    |   File "/usr/lib/python3/dist-packages/django/core/files/storage.py", line 54, in save
components    |     return self._save(name, content)
components    |   File "/usr/lib/python3/dist-packages/django/core/files/storage.py", line 326, in _save
components    |     raise IOError("%s exists and is not a directory." % directory)
components    | OSError: /var/lib/combo/collectstatic/xstatic/fonts/SemiboldItalic exists and is not a directory.