add shell script to revoke DK as requested by Florian for revocation testing via taler-wallet-cli

contrib/taler-exchange-revoke

@@ -0,0 +1,24 @@
+#!/bin/sh
+# This file is in the public domain
+#
+# Used to first revoke a key and then restart the exchange
+# to ensure it notices the revocation.
+#
+# Takes 2 arguments:
+# $1: the configuration file name
+# $2: the denomination key hash (DKH) of the denomination to revoke
+
+set -eu
+
+if [ "$#" -ne 2 ];
+then
+  echo "illegal number of parameters"
+  exit 1
+fi
+
+taler-exchange-keyup -c $1 -r $2
+
+EXCHANGE_PID=`ps x | grep taler-exchange-httpd | awk '{print $1}'`
+kill -HUP $EXCHANGE_PID
+
+exit 0