Add redis password parameter

Redis server API was not protected with a password
by default.
To fix this issue we need to provide a way to
configure redis with authentification in salt-formula.
This patch addresses the problem for redis used
by contrail analytics.
If redis password is not set in the model then redis
will be configured without password.

Co-Authored-By Gleb Zimin <gzimin@mirantis.com>
Co-Authored-By Pavel Svimbersky <psvimbersky@mirantis.com>

Change-Id: I05813169be38ece1bd592d73a3ba1f4c7502d602
Related-Prod: PROD-22096
diff --git a/README.rst b/README.rst
index e285e13..c8724e4 100644
--- a/README.rst
+++ b/README.rst
@@ -122,6 +122,11 @@
           address: 127.0.0.1
         master:
           host: 127.0.0.1
+        contrail_cache:
+          engine: redis
+          host: 127.0.0.1
+          port: 6379
+          password: guest
         discovery:
           host: 127.0.0.1
         data_ttl: 2
@@ -168,6 +173,7 @@
         cache:
           engine: redis
           host: 127.0.0.1
+          password: guest
           port: 6379
         members:
         - host: 127.0.0.1
@@ -280,6 +286,11 @@
           address: 127.0.0.1
         master:
           host: 127.0.0.1
+        contrail_cache:
+          engine: redis
+          host: 127.0.0.1
+          port: 6379
+          password: guest
         discovery:
           host: 127.0.0.1
         data_ttl: 1
@@ -332,6 +343,7 @@
         cache:
           engine: redis
           host: 127.0.0.1
+          password: guest
           port: 6379
         members:
         - host: 127.0.0.1
@@ -473,6 +485,7 @@
         cache:
           engine: redis
           host: 127.0.0.1
+          password: guest
           port: 6379
         members:
         - host: 127.0.0.1
@@ -515,6 +528,11 @@
         enabled: true
         bind:
           address: 127.0.0.1
+        contrail_cache:
+          engine: redis
+          host: 127.0.0.1
+          password: guest
+          port: 6379
         master:
           host: 127.0.0.1
         discovery: