Fix Doc mistakes and add log to gitignore.

This commit is to fix few gaps in documentation.

Change-Id: I20021bdfb94d143f21a17dac77ee157fec7ab0af
diff --git a/README.rst b/README.rst
index dfba71f..becc078 100644
--- a/README.rst
+++ b/README.rst
@@ -188,7 +188,7 @@
 ``rbac_test_roles`` in the ``patrole`` section of tempest.conf: ::
 
     [patrole]
-    rbac_test_role = member,reader
+    rbac_test_roles = member,reader
     ...
 
 .. note::