NEWS: update NEWS file

Plug a memory leak in MPI_Mem_free().  Thanks to Philip Blakely for reporting.

Refs 87b2720

Signed-off-by: Gilles Gouaillardet <[email protected]>

Author: ggouaillardet

NEWS

@@ -53,6 +53,13 @@ included in the vX.Y.Z section and be denoted as:
    (** also appeared: A.B.C)  -- indicating that this item was previously
                                  included in release version vA.B.C.
 
+2.1.3 -- To be released
+------------------------
+
+Bug fixes/minor improvements:
+
+- Plug a memory leak in MPI_Mem_free().  Thanks to Philip Blakely for reporting.
+
 2.1.2 -- September, 2017
 ------------------------