emit on worker completion

with test

src/helpers/constants.js

@@ -17,6 +17,7 @@ export const events = {
   EVENT_JOB_CREATED: 'job:created',
   EVENT_JOB_ERROR: 'job:error',
   EVENT_WORKER_ERROR: 'worker:error',
+  EVENT_WORKER_COMPLETE: 'worker:job complete',
   EVENT_WORKER_JOB_CLAIM_ERROR: 'worker:claim job error',
   EVENT_WORKER_JOB_SEARCH_ERROR: 'worker:pending jobs error',
   EVENT_WORKER_JOB_UPDATE_ERROR: 'worker:update job error',

src/worker.js

@@ -195,6 +195,7 @@ export default class Job extends events.EventEmitter {
         version: job._version,
         body: { doc }
       })
+      .then(() => this.emit(constants.EVENT_WORKER_COMPLETE, Object.assign(emitJob, { output: docOutput })))
       .catch((err) => {
         if (err.statusCode === 409) return false;
         this.debug(`Failure saving job output ${job._id}`, err);