Deprecate bulk duplicate option

This feature is now enabled by default in the Community Console, so this
commit removes the option which let users enable the feature manually.

Change-Id: I57c5e20a446ee784b72018ca71735fd40fa31471
diff --git a/src/options.js b/src/options.js
index 2bcd96f..1a321b4 100644
--- a/src/options.js
+++ b/src/options.js
@@ -20,7 +20,8 @@
 const deprecatedOptions = [
   "list",
   "escalatethreads",
-  "movethreads"
+  "movethreads",
+  "batchduplicate"
 ];
 
 function cleanUpOptions(options) {