Update readme to reflect masters current state.

Author: pmienk

README.md

@@ -1,19 +1 @@
-[![Build Status](https://travis-ci.org/libbitcoin/libbitcoin-node.svg?branch=master)](https://travis-ci.org/libbitcoin/libbitcoin-node)
-
-[![Coverage Status](https://coveralls.io/repos/libbitcoin/libbitcoin-node/badge.svg)](https://coveralls.io/r/libbitcoin/libbitcoin-node)
-
-# Libbitcoin Node
-
-*Bitcoin full node based on libbitcoin-blockchain*
-
-Make sure you have installed [libbitcoin-blockchain](https://github.com/libbitcoin/libbitcoin-blockchain) and [libbitcoin-network](https://github.com/libbitcoin/libbitcoin-network) beforehand according to their build instructions.
-
-```sh
-$ ./autogen.sh
-$ ./configure
-$ make
-$ sudo make install
-$ sudo ldconfig
-```
-
-libbitcoin-node is now installed in `/usr/local/`.
+This branch is not usable in its current state. Please see [version3](https://github.com/libbitcoin/libbitcoin-node/tree/version3) for the latest functional branch.