Fixes API unit tests

Fix all unit tests, and use a `testcfg.ini` file to load test
configuration values (e.g. api_client, url, ...)

wallabag_api/wallabag.py

@@ -380,7 +380,7 @@ class Wallabag(object):
         Permanently remove one tag for an entry
 
         :param entry: \w+ an integer The Entry ID
-        :param tag: string The Tag
+        :param tag: integer The Tag ID
         :return data related to the ext
         """
         params = {'access_token': self.token}