Prep for 3.1.2 of CPS

- updated release notes
- bumbed cps version to 3.1.2-SNAPSHOT from 3.1.1-SNAPSHOT

Issue-ID: CPS-1304
Change-Id: Ie65f76032b087dffc716e00fa3868f89f165a6b1
Signed-off-by: mpriyank <priyank.maheshwari@est.tech>
diff --git a/docs/release-notes.rst b/docs/release-notes.rst
index 5d3aa92..d3c2176 100755
--- a/docs/release-notes.rst
+++ b/docs/release-notes.rst
@@ -16,6 +16,30 @@
 ..      * * *   KOHN   * * *
 ..      ====================
 
+Version: 3.1.2
+==============
+
+Release Data
+------------
+
++--------------------------------------+--------------------------------------------------------+
+| **CPS Project**                      |                                                        |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+| **Docker images**                    | onap/cps-and-ncmp:3.1.2                                |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+| **Release designation**              | 3.1.2 Kohn                                             |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+| **Release date**                     | (yet to release)                                       |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+
+Bug Fixes
+---------
+   - None
+
 Version: 3.1.1
 ==============
 
@@ -32,7 +56,7 @@
 | **Release designation**              | 3.1.1 Kohn                                             |
 |                                      |                                                        |
 +--------------------------------------+--------------------------------------------------------+
-| **Release date**                     | (yet to release)                                       |
+| **Release date**                     | 2022 September 28                                      |
 |                                      |                                                        |
 +--------------------------------------+--------------------------------------------------------+