Fix some conflicts with vim-go and COC
Fix some conflicts with vim-go and COC

Use COC for most go and LSP related stuff.
COC sits on top of gopls, which is installed by vim-go's `:GoInstallBinaries`
command.

Disable some features of vim-go which were conflicting with COC.

rtucek/dotfiles,rtucek/dotfiles,rtucek/dotfiles