Add clone script and shared bash script config

clone.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+BASEDIR=$(dirname "$0")
+cd "${BASEDIR}"
+BASEDIR=`pwd`
+
+source config.sh
+
+set -x
+
+if [ ! -d "${UPSTREAM_DIR}" ]; then
+    git clone ${UPSTREAM_REPO} ${UPSTREAM_DIR}
+fi
+
+if [ ! -d "${MMC_DIR}" ]; then
+    git clone ${MMC_REPO} ${MMC_DIR}
+fi

config.sh

@@ -0,0 +1,5 @@
+export UPSTREAM_DIR=mojang
+export UPSTREAM_REPO=git@github.com:MultiMC/meta-upstream.git
+export MMC_DIR=multimc
+export MMC_REPO=git@github.com:MultiMC/meta-multimc.git
+

update.sh

@@ -6,8 +6,7 @@ BASEDIR=`pwd`
 
 set -x
 
-export UPSTREAM_DIR=mojang
-export MMC_DIR=multimc
+source config.sh
 
 function fail {
     git reset --hard HEAD