[CLA] signature for serenite24h24

closes odoo/odoo#39621

Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

doc/cla/corporate/serenite24h24.md

+France, 31/10/2019
+
+SERENITE 24H24 agrees to the terms of the Odoo Corporate Contributor License
+Agreement v1.0.
+
+I declare that I am authorized and able to make this agreement and sign this
+declaration.
+
+Signed,
+
+Arnaud Willem arnaud@jaunedemars.fr https://github.com/a-willem
+
+List of contributors:
+
+Arnaud Willem arnaud@jaunedemars.fr https://github.com/a-willem