Added error handling for suspend and resume vm

            raise VMError('%s is already running !' % self.get_name())

    def suspend(self):

        try:

            self._domain.suspend()

        except libvirt.libvirtError:

            raise VMError('%s is not running !' % self.get_name())

    def resume(self):

        try:

            self._domain.resume()

        except libvirt.libvirtError:

            raise VMError('%s is not running !' % self.get_name())

    def get_uuid(self):

        '''