bundle/nerdtree seems to be a submodule
Revert "Installed the NERD tree : A tree explorer plugin for navigating the"

This reverts commit 4c69d12488925c7ce557f335673bd905db0da9b7.
Installed the NERD tree : A tree explorer plugin for navigating the
filesystem.
https://github.com/scrooloose/nerdtree