message: add dawn4.2 readme
diff: @@ -173,9 +173,9 @@ run `docker pull eosio/eos:latest`
  run `docker-compose up`
  -### Dawn 4.0 Testnet
  +### Dawn 4.2 Testnet
  -We can easily set up a Dawn 4.0 local testnet using docker images. Just run the following commands:
  +We can easily set up a Dawn 4.2 local testnet using docker images. Just run the following commands:
  Note: if you want to use the mongo db plugin, you have to enable it in your `data-dir/config.ini` first.
  @@ -188,13 +188,13 @@ docker volume create --name=nodeos-data-volume
  docker volume create --name=keosd-data-volume
  docker volume create --name=mongo-data-volume
  # start containers
  -docker-compose -f docker-compose-dawn4.0.yaml up -d
  +docker-compose -f docker-compose-dawn4.2.yaml up -d
  # get chain info
  curl http://127.0.0.1:8888/v1/chain/get_info
  # get logs
  docker-compose logs nodeosd
  # stop containers
  -docker-compose -f docker-compose-dawn4.0.yaml down
  +docker-compose -f docker-compose-dawn4.2.yaml down
  ```
  The `blocks` data are stored under `--data-dir` by default, and the wallet files are stored under `--wallet-dir` by default, of course you can change these as you want.
  