add build script for the project

add build script for nova-zvm-virt-driver to build rpm packages
with using speciifed version format.

Change-Id: I8322d2cf134b996689f092b1e7a0a3693f506421

tools/build_rpm.sh

@@ -0,0 +1,16 @@
+#! /bin/sh
+
+export PBR_VERSION="2015.1"
+
+if [ $# == 0 ]; then
+    echo "You should provide project top dir."
+    read TOP_DIR
+fi
+
+TOP_DIR=${TOP_DIR:-$1}
+RELEASE=`date "+%Y%m%d"`
+
+cd ${TOP_DIR}
+
+rm -f ${TOP_DIR}/dist/*
+python setup.py bdist_rpm --release ${RELEASE}