chore: deprecate version_date

Author: germanattanasio

lib/middleware/index.js

@@ -33,6 +33,12 @@ module.exports = function (config) {
     throw new Error('Watson Assistant config parameters absent.');
   }
 
+  if (config.version_date) {
+    console.warn('"version_date" is deprecated and will be removed in the next major release. Use "version"');
+    config.version = config.version_date;
+    delete config.version_date;
+  }
+
   var middleware = {
 
     minimum_confidence: (config.minimum_confidence || 0.75),