move build time into image build function

'''

import os

import time

import datetime

import re

import fnmatch

            os.chdir(path)

            path = "."

        arrowlevel(1)

        # build start time

        t0 = time.time()

        # load source image

        simg = SourceImage(path)

        # do the job

        simg.build(force=args.force, force_payload=args.payload,

        dt = simg.build(force=args.force, force_payload=args.payload,

                        check=not args.no_check, script=not args.no_script)

        # compute building time

        t1 = time.time()

        dt = int(t1 - t0)

        arrow(u"Build time: %s" % datetime.timedelta(seconds=dt))

        if args.chdir:

            os.chdir(cwd)

        # check if free to create script tarball

        if os.path.exists(self.image_name) and force == False:

            raise ISError("Tarball already exists. Remove it before")

        # register start time

        t0 = time.time()

        # check python scripts

        if check:

            for d in (self.build_path, self.parser_path, self.setup_path):

        jdesc = self.generate_json_description()

        # creating scripts tarball

        self.create_image(jdesc)

        # compute building time

        return int(time.time() - t0)

    def create_image(self, jdescription):

        '''