[doc] rustc 1.47+ is required

README.md

 ![Duniter logo](https://git.duniter.org/nodes/typescript/duniter/raw/dev/images/250%C3%97250.png)
 
-# Duniter [![build status](https://git.duniter.org/nodes/typescript/duniter/badges/dev/pipeline.svg)](https://git.duniter.org/nodes/typescript/duniter/commits/dev) [![Coverage Status](https://coveralls.io/repos/github/duniter/duniter/badge.svg?branch=master)](https://coveralls.io/github/duniter/duniter?branch=master) [![Dependencies](https://david-dm.org/duniter/duniter.svg)](https://david-dm.org/duniter/duniter)
+# Duniter [![build status](https://git.duniter.org/nodes/typescript/duniter/badges/dev/pipeline.svg)](https://git.duniter.org/nodes/typescript/duniter/commits/dev) [![Coverage Status](https://coveralls.io/repos/github/duniter/duniter/badge.svg?branch=master)](https://coveralls.io/github/duniter/duniter?branch=master) [![Dependencies](https://david-dm.org/duniter/duniter.svg)](https://david-dm.org/duniter/duniter) [![Minimum rustc version](https://img.shields.io/badge/rustc-1.47.0+-yellow.svg)](https://github.com/rust-lang/rust/blob/master/RELEASES.md)
 
 Duniter (previously uCoin) is a libre software allowing to create a new kind of P2P crypto-currencies based on individuals and Universal Dividend.
 

rust-bins/xtask/src/main.rs

@@ -19,7 +19,7 @@ use std::{
 };
 use structopt::StructOpt;
 
-const MIN_RUST_VERTION: &str = "1.46.0";
+const MIN_RUST_VERTION: &str = "1.47.0";
 const NODE_VERSION: &str = "10.22.1";
 const NVM_VERSION: &str = "0.35.3";