Update earliest-version number format in release notes

Rodolfo Alonso Hernandez · Rodolfo Alonso Hernandez · commit 5084ce14b0b9 · 2016-12-22T13:49:27.000Z
Change-Id: I67deca8d2ff1f63d272b8d5b78cb31efd6e6d4df
Closes-Bug: #1652054
diff --git a/releasenotes/source/unreleased.rst b/releasenotes/source/unreleased.rst
@@ -3,4 +3,4 @@ Current Release Notes
 =====================
 
 .. release-notes::
-   :earliest-version: 3.0
+   :earliest-version: 3.0.0
