Creates k8s deployment that executes Teraslice workers for specified
Execution.
@param  {Object} execution  Object that contains information of Execution
@return {Promise}           [description]
function allocateWorkers(execution) {
        const kr = new K8sResource(
            'deployments', 'worker', context.sysconfig.teraslice, execution
        );

        const workerDeployment = kr.resource;

        logger.debug(`workerDeployment:\n\n${JSON.stringify(workerDeployment, null, 2)}`);

        return k8s.post(workerDeployment, 'deployment')
            .then(result => logger.debug(`k8s worker deployment submitted: ${JSON.stringify(result)}`))
            .catch((err) => {
                const error = new TSError(err, {
                    reason: 'Error submitting k8s worker deployment'
                });
                return Promise.reject(error);
            });
    }