add CHANGELOG

README.md

@@ -109,3 +109,18 @@ Each route is available as a GET request, as a JSONRPCv2 POST request, and via J
 
 * [Tendermint](https://github.com/tendermint/tendermint/blob/master/rpc/core/routes.go)
 * [Network Monitor](https://github.com/tendermint/netmon/blob/master/handlers/routes.go)
+
+## CHANGELOG
+
+### 0.7.0
+
+BREAKING CHANGES:
+
+- removed `Client` empty interface
+- `ClientJSONRPC#Call` `params` argument became a map
+
+IMPROVEMENTS:
+
+- added `HTTPClient` interface, which can be used for both `ClientURI`
+and `ClientJSONRPC`
+- all params are now optional (Golang's default will be used if some param is missing)