message: Update note on v0.5/0.6/0.7
diff: This repo provides a useful functionality to build smart contracts that
  are compatible with Cosmos SDK runtime, [currently being developed](https://github.com/cosmwasm/cosmos-sdk/issues).
  -**Warning** Most likely you want to check out `v0.5.2` tag, the stable release referred to in the [documention](https://www.cosmwasm.com).
  -We are currently on `v0.6.0` with many breaking API changes, soon we will update the tutorials. (Along with a v0.7.0 release)
  +**Note** Compiling with `v0.6.3+` will produce contracts compatible with the
  +[`wasmd`](https://github.com/cosmwasm/wasmd) blockchain. There is no active development on
  +master (0.6.x) branch except for bugfixes if needed. Development is targetting the `0.7`
  +*branch*, which is the next planned, breaking release.
  ## Overview
  