add git wg update

git-wg-peer-update

@@ -0,0 +1,13 @@
+#!/bin/bash
+PEER=$1
+KEY=$2
+VALUE=$3
+
+set -e
+FNAME=$(echo $PEER.wg | sed -e 's/[^A-Za-z0-9._-]/_/g')
+
+sed -i "s/$KEY =.*/$KEY = $VALUE/g" "$FNAME"
+
+
+git add "$FNAME"
+git commit -m "update $KEY of peer $PEER to $VALUE"