👨‍💻 Address issues from #57 + remove underscore dependency

Thank you @jankapunkt, let me know wdyt?

Author: dr-dimitru

lib/client/fileUpload.js

@@ -1,4 +1,3 @@
-import { _ }           from 'meteor/underscore';
 import { Meteor }      from 'meteor/meteor';
 import { AutoForm }    from 'meteor/aldeed:autoform';
 import { Template }    from 'meteor/templating';
@@ -52,15 +51,19 @@ Template.afFileUpload.onCreated(function () {
   this.uploadTemplate  = this.data.atts.uploadTemplate || null;
   this.previewTemplate = this.data.atts.previewTemplate || null;
   this.accept          = this.data.atts.accept || null;
-  this.insertConfig    = Object.assign({}, this.data.atts.insertConfig || {});
+  this.insertConfig    = Object.assign({}, defaultInsertOpts, this.data.atts.insertConfig || {});
   delete this.data.atts.insertConfig;
-  this.insertConfig    = Object.assign(this.insertConfig, _.pick(this.data.atts, Object.keys(defaultInsertOpts)));
 
-  if (!isNaN(this.insertConfig.streams) || this.insertConfig.streams !== 'dynamic') {
+  if (!isNaN(this.insertConfig.streams)) {
     this.insertConfig.streams = parseInt(this.insertConfig.streams);
+  } else if (this.insertConfig.streams !== 'dynamic') {
+    this.insertConfig.streams = 'dynamic';
   }
-  if (!isNaN(this.insertConfig.chunkSize) || this.insertConfig.chunkSize !== 'dynamic') {
+
+  if (!isNaN(this.insertConfig.chunkSize)) {
     this.insertConfig.chunkSize = parseInt(this.insertConfig.chunkSize);
+  } else if (this.insertConfig.chunkSize !== 'dynamic') {
+    this.insertConfig.chunkSize = 'dynamic';
   }
 
   this.collectionName = function () {