try to correct appdi install probel (cf https://github.com/ActiveState/appdirs/issues/89)
--- a/src/requirements/base.txt Thu Mar 16 13:02:58 2017 +0100
+++ b/src/requirements/base.txt Thu Mar 16 13:14:35 2017 +0100
@@ -1,4 +1,4 @@
-appdirs==1.4.0
+appdirs==1.4.3
Django==1.10.5
django-comments-xtd==1.6.3
django-contrib-comments==1.7.3