Squashed 'vim/plugins/vim-go/' content from commit 27a8b46

git-subtree-dir: vim/plugins/vim-go
git-subtree-split: 27a8b46fb98657bd3de79d610b1eb61709ee04df
Merge commit '91db4c6de2fbcffd18120477f3e847dbc1927f96' as 'vim/plugins/vim-go'
Update iterm config for tmux
Add tmux config
Update vimrc
Update PATH; docker config and other cask apps