Fix doc build warnings

Issue-ID: DCAEGEN2-516
Change-Id: I94f1c7fcf5e4a21752c3ce9d8d71d98f2140e1ee
Signed-off-by: Lusheng Ji <lji@research.att.com>
diff --git a/docs/sections/blueprints/inventoryapi.rst b/docs/sections/blueprints/inventoryapi.rst
index 016ecce..cdbc164 100644
--- a/docs/sections/blueprints/inventoryapi.rst
+++ b/docs/sections/blueprints/inventoryapi.rst
@@ -19,5 +19,5 @@
 Cfy command for running the blueprint
 
 Additional Information
----------------------
+----------------------
 Any additional information that help other people understanding and using yor blueprint