Add USE_FAKE_SDL to mock the data storage layer

This new environment variable in the Dockerfile exposes existing
functionality in the data module. Default is False, the current behavior.
Set to True to work with A1 Mediator standalone.

Issue-ID: RIC-351
Signed-off-by: Lott, Christopher (cl778h) <cl778h@att.com>
Change-Id: I7efbe325e3c9536181c95eec63662d7a98a29ff4
diff --git a/docs/release-notes.rst b/docs/release-notes.rst
index f793d02..8febae6 100644
--- a/docs/release-notes.rst
+++ b/docs/release-notes.rst
@@ -23,6 +23,7 @@
 * Add tiny RMR routing table for use in demo and test
 * Extend documentation for running a container locally
 * Add documentation of start/init parameters to _RmrLoop class
+* Add new environment variable USE_FAKE_SDL (`RIC-351 <https://jira.o-ran-sc.org/browse/RIC-351>`_)
 
 
 [2.1.7] - 2020-04-28