docs updates

docs/installation.rst

@@ -254,6 +254,7 @@ Then adjust the database schema (if changed) by running the migrations::
 and install any dependencies (if changed)::
 
     pip install --upgrade -r requirements/base.txt
+    pip install --upgrade -r requirements/production.txt
 
 Finally run the **collectstatic** command to copy updated assets into the web server's folder::