Install rustup in common.docker

imagefiles/build-and-install-rustup.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if ! command -v curl &> /dev/null; then
+	echo >&2 'error: "curl" not found!'
+	exit 1
+fi
+
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y