build-deploy: use bash interpreter

Change-Id: I23e139f6cbd98c360a3dadac611ad856e975fda2
diff --git a/build-deploy.sh b/build-deploy.sh
index bf4b859..7fb442f 100644
--- a/build-deploy.sh
+++ b/build-deploy.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # this script packages up all the binaries, and a script (deploy.sh)
 # to twiddle with the server and the binaries