Formally release version 0.2.1 of the spec

Change-Id: Ia1bce45d7699a13ac299b38f3bd8fd94f0558e4f
diff --git a/changelog.rst b/changelog.rst
index f72e0ae..0184781 100644
--- a/changelog.rst
+++ b/changelog.rst
@@ -1,8 +1,8 @@
 Changes
 =======
 
-Since version 0.2
------------------
+Version 0.2.1
+-------------
 
 - Add definition of Link Object
 
@@ -17,8 +17,8 @@
 
 ************************************************************
 
-Since version 0.1.1
--------------------
+Version 2.0
+-----------
 
 - **Name**
 
@@ -44,8 +44,8 @@
 
 ************************************************************
 
-Since version 0.1
------------------
+Version 0.1.1
+-------------
 
 - **Signature**
 
@@ -56,8 +56,8 @@
 
 ************************************************************
 
-Since CCNx 0.7.2
-----------------
+Version 0.1
+-----------
 
 - **General**