Issues with UpdateBundles ruby script and having your own plugin

[AndreyKozlov1984]

I've created my own git plugin and published it on the githhub - git@github.com:ZeusTheTrueGod/vim-format-js.git
Locally plugin is stored in some folder not inside the startervim working copy

After that I connected it with a BUNDLE syntax in a .vimrc file
When I execute a :UpdateBundles first time the plugin is cloned in the bundle directory and everything is fine. Now I add changes to my plugin and do git commit + git push origin master for my plugin.

I execute :UpdateBundles from vim and see that fetch is executed, so that is fine. But I have a notice when I explicitly execute a 'git checkout master' in the strartervim/bundle directory
Your branch is behind 'origin/master' by 2 commits, and can be fast-forwarded.

In fact, my plugin is not updated unless I also call git merge or git pull
So I think that git pull(or git merge?) should be executed instead of git checkout