Add a `/clean` route

Add a route to clean temporary downloaded files (actually deletes all
temporary folders created by cozyweboob).

README.md

@@ -54,6 +54,11 @@ It exposes a couple of routes:
 
 * the `/retrieve` route, which supports `POST` method and a single `path` `POST`
   parameter which is the path to the previously downloaded file to retrieve.
+  Note that this route will not delete the temporary file whose content has
+  been retrieved, and you should delete it manually.
+
+* the `/clean` route, which will delete all temporary downloaded files. This
+  route will return a JSON list of deleted folders.
 
 **IMPORTANT:** Note this small webserver is **not** production ready and only
 here as a proof of concept and to be used in a controlled development

server.py

@@ -4,6 +4,7 @@ HTTP server wrapper around weboob
 """
 import logging
 import os
+import shutil
 import tempfile
 
 from bottle import post, request, route, run, static_file
@@ -40,6 +41,29 @@ def retrieve_view():
                        download=True)
 
 
+@route("/clean")
+def clean_view():
+    """
+    Delete all the temporary downloaded files. These are the
+    "cozyweboob-*-tmp" folders in your system tmp dir.
+    """
+    sys_tmp_dir = tempfile.gettempdir()
+    tmp_dirs = [
+        x
+        for x in os.listdir(sys_tmp_dir)
+        if os.path.isdir(os.path.join(sys_tmp_dir, x))
+    ]
+    removed_dirs = []
+    for tmp_dir in tmp_dirs:
+        if tmp_dir.startswith("cozyweboob-") and tmp_dir.endswith("-tmp"):
+            tmp_dir = os.path.join(sys_tmp_dir, tmp_dir)
+            removed_dirs.append(tmp_dir)
+            shutil.rmtree(tmp_dir)
+    return {
+        "removed_dirs": removed_dirs
+    }
+
+
 @route("/list")
 def list_view():
     """