Detect the option highlight in Discovery node

Author: chughts

README.md

@@ -9,8 +9,9 @@ Node-RED Watson Nodes for IBM Cloud
 
 ### New in version 0.6.8
 - Move all Discovery calls to latest API version - 2017-11-07
-- Updated calls to deprecated discovery methods addJsonDocument and getCollections 
+- Updated calls to deprecated discovery methods addJsonDocument and getCollections
 - Correct implemetation of passages related options
+- Allow highlight option to be specified in Discovery overrides - msg.discoveryparams 
 
 ### New in version 0.6.7
 - Enable Opt-out option for Conversation Node.

services/discovery/discovery-utils.js

@@ -125,7 +125,8 @@ DiscoveryUtils.prototype = {
 
     ['environment_id', 'collection_id', 'configuration_id',
       'collection_name', 'language_code',
-      'passages', 'description', 'size', 'filename'
+      'passages', 'description', 'size', 'filename',
+      'highlight'
     ].forEach(function(f) {
       params = me.buildParamsFor(msg, config, params, f);
     });