Vundle `PluginInstall` from shell

Want to install your latest vim plugins without having to interact with vim and vundle? The following command will install your latest Vundle plugins without any user interaction with Vim. I'm using this to install my Vim plugins in a Docker build script

$ vim -c 'PluginInstall' -c 'qa!'

The -c option allows one to run a command before Vim starts up, and you can have up to 32 -c commands, according to the man page. So this snippet tells Vim to run the PluginInstall command (from Vundle) and then qa! to quit all windows.