Update CHANGELOG

Author: ethanfrey

CHANGELOG.md

@@ -47,6 +47,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking
 
+* (modules) [\#206](https://github.com/cosmos/ibc-go/pull/206) Expose `relayer sdk.AccAddress` on `OnRecvPacket`, `OnAcknowledgementPacket`, `OnTimeoutPacket` module callbacks to enable incentivization.
 * (02-client) [\#181](https://github.com/cosmos/ibc-go/pull/181) Remove 'InitialHeight' from UpdateClient Proposal. Only copy over latest consensus state from substitute client.
 * (06-solomachine) [\#169](https://github.com/cosmos/ibc-go/pull/169) Change FrozenSequence to boolean in solomachine ClientState. The solo machine proto package has been bumped from `v1` to `v2`.
 * (module/core/02-client) [\#165](https://github.com/cosmos/ibc-go/pull/165) Remove GetFrozenHeight from the ClientState interface.