add md5 sum check for Voro++ download via Install.py

from __future__ import print_function

import sys,os,re,subprocess,shutil

sys.path.append('..')

from install_helpers import get_cpus,fullpath,geturl

from install_helpers import get_cpus,fullpath,geturl,checkmd5sum

from argparse import ArgumentParser

parser = ArgumentParser(prog='Install.py',

version = "voro++-0.4.6"

url = "http://math.lbl.gov/voro++/download/dir/%s.tar.gz" % version

# known checksums for different Voro++ versions. used to validate the download.

checksums = { \

        'voro++-0.4.6' : '2338b824c3b7b25590e18e8df5d68af9' \

        }

# extra help message

help = """

  print("Downloading Voro++ ...")

  geturl(url,"%s/%s.tar.gz" % (homepath,version))

  # verify downloaded archive integrity via md5 checksum, if known.

  if version in checksums:

    if not checkmd5sum(checksums[version],'%s/%s.tar.gz' % (homepath,version)):

      sys.exit("Checksum for Voro++ library does not match")

  print("Unpacking Voro++ tarball ...")

  if os.path.exists("%s/%s" % (homepath,version)):

    shutil.rmtree("%s/%s" % (homepath,version))