fix case of WithRevCheck method

services/docstore/app/js/DocManager.js

@@ -172,7 +172,7 @@ module.exports = DocManager = {
       if (err) {
         return callback(err)
       }
-      MongoManager.WithRevCheck(
+      MongoManager.withRevCheck(
         doc,
         MongoManager.getDocVersion,
         function (error, version) {

services/docstore/app/js/MongoManager.js

@@ -199,7 +199,7 @@ module.exports = MongoManager = {
   // Helper method  to support optimistic locking. Call the provided method for
   // an existing doc and return the result if the rev in mongo is unchanged when
   // checked afterwards. If the rev has changed, return a DocModifiedError.
-  WithRevCheck(doc, method, callback) {
+  withRevCheck(doc, method, callback) {
     method(doc._id, function (err, result) {
       if (err) return callback(err)
       MongoManager.getDocRev(doc._id, function (err, currentRev) {