Install the app to the virtualenv

def install_program(self, extra_args):
        """Install the app to the virtualenv"""
        pip = Command(path.join(self.env, 'bin', 'pip'))
        args = ['install', self.raw_name,
                '--install-option', '--install-scripts={}'
                .format(self.env_bin)] + list(extra_args)
        print_pretty("<BOLD>pip {}<END>\n".format(' '.join(args)))
        pip(args, _out=sys.stdout, _err=sys.stderr)
        print('')