reduce docker image size a bit

docker/install-aur-package.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+for PACKAGE in "$@"; do
+    BUILD_DIR="$(mktemp -d)"
+    git clone https://aur.archlinux.org/"$PACKAGE".git "$BUILD_DIR"
+    cd "$BUILD_DIR"
+    makepkg --noconfirm --install --rmdeps --syncdeps
+    cd /
+    rm -r "$BUILD_DIR"
+done