add recognizer.azureServiceEndpoint for custom azure voices

lib/tasks/say.js

@@ -164,6 +164,10 @@ class TaskSay extends Task {
           'tts.voice': voice
         });
         try {
+          if (vendor === 'microsoft' && this.synthesizer.azureServiceEndpoint) {
+            credentials.use_custom_tts = true;
+            credentials.custom_tts_endpoint = this.synthesizer.azureServiceEndpoint;
+          }
           const {filePath, servedFromCache} = await synthAudio(stats, {
             text,
             vendor,

lib/tasks/specs.json

@@ -435,7 +435,8 @@
       "gender": {
         "type": "string",
         "enum": ["MALE", "FEMALE", "NEUTRAL"]
-      }
+      },
+      "azureServiceEndpoint": "string"
     },
     "required": [
       "vendor"