Add logging_json

Output odoo logs as json

README.md

@@ -24,6 +24,7 @@ Libraries that must be added in ``requirements.txt``:
 ```
 boto==2.42.0
 redis==2.10.5
+python-json-logger==0.1.5
 ```
 
 ### Server Environment
@@ -75,6 +76,13 @@ Besides, the
  * `ODOO_SESSION_REDIS_PREFIX`: `<client>-odoo-test`
  * `ODOO_SESSION_REDIS_EXPIRATION`: `86400` (1 day)
 
+### JSON Logging
+
+At least on production and integration, activate:
+* `ODOO_LOGGING_JSON`: 1
+* Add ``logging_json`` in the ``server_wide_modules`` option in the
+  configuration file
+
 ### Automatic Configuration
 
 Calling `ctx.env['cloud.platform'].install_exoscale()` in an