Add ChangeLog

Add ChangLog item, describing the feature

Signed-off-by: Johan Pascal <johan.pascal@belledonne-communications.com>
diff --git a/ChangeLog b/ChangeLog
index 594c3cf..69e094c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -730,6 +730,10 @@
    * Ciphersuites based on 3DES now have the lowest priority by default when
      they are enabled.
 
+Features
+   * Add support for DTLS-SRTP as defined in RFC 5764. Based on contribution done
+     by Johan Pascal in #361.
+
 = mbed TLS 2.16.0 branch released 2018-12-21
 
 Features