build handler in travis (Controller refactorization)

[tomsou]

In the frame of Controller refactorization the build handler is wrapped
via class methon build().

This implementation runs successfully in jenkins, however it fails in travis

There is a paradox issue here, which may concerns a limitation in travis ci:
the build handler is executed successfully when it is called as a bash script:
- sudo bash ./controllers/odl_beryllium_pb/build.sh
However, it fails when it (the same script) is called within python wrapper class method:

Controller.py

    def build(self):
        """ Wrapper to the controller build handler
        """
        logging.info('[Controller] Building')
        self.status = 'BUILDING'

        exit_status = util.netutil.ssh_run_command(self._ssh_conn,
                                    ' '.join([self.build_hnd]),
                                    '[controller.build_handler]')[0]
        if exit_status == 0:
            self.status = 'BUILT'
            logging.info("[Controller] Successful building")
        else:
            self.status = 'NOT BUILT'
            logging.error("[Controller] Failure during building")
            raise Exception('[Controller] Failure during building')