collect indexSettings on queue creation, pass to job and use at index creation

src/index.js

@@ -45,7 +45,8 @@ export default class Esqueue extends events.EventEmitter {
     };
 
     const options = Object.assign(defaults, opts, {
-      doctype: this.settings.doctype
+      doctype: this.settings.doctype,
+      indexSettings: this.settings.indexSettings,
     });
 
     return new Job(this.client, index, type, payload, options);

src/job.js

@@ -25,6 +25,7 @@ export default class Job extends events.EventEmitter {
     this.maxAttempts = options.max_attempts || 3;
     this.priority = Math.max(Math.min(options.priority || 10, 20), -20);
     this.doctype = options.doctype || contstants.DEFAULT_SETTING_DOCTYPE;
+    this.indexSettings = options.indexSettings || {};
 
     this.debug = (...msg) => debug(...msg, `id: ${this.id}`);
 
@@ -48,7 +49,7 @@ export default class Job extends events.EventEmitter {
 
     if (options.headers) indexParams.headers = options.headers;
 
-    this.ready = createIndex(this.client, this.index, this.doctype)
+    this.ready = createIndex(this.client, this.index, this.doctype, this.indexSettings)
     .then(() => this.client.index(indexParams))
     .then((doc) => {
       this.document = {