This assumes you're using some version of macOS.
First brew install the following:
brew install make
brew install tmux
brew install vim
brew install ack
brew install reattach-to-user-namespace
From within this cloned repository run:
make all
make vimplugins
If you don't already have a ~/.bash_profile create it. Add to it:
source .bashrc
To install YCM run:
cd resources/vim/bundle/YouCompleteMe
git submodule update --init --recursive;
./install.py --tern-completer