go and vim-go

sudo apt-get install golang golang-golang-x-tools golint

• set GOPATH in .bashrc, such as ~/go, where bin, pkg, src will be put
• use vundle to download vim-go from
  https://github.com/fatih/vim-go
• In vim, run :GoInstallBinaries
  It will complain unable to download some, but so far it is enough for most functionalities.
  Saving a .go file will invoke gofmt.
  ^x^o to auto complete
  :GoDef
  :GoBuild
  :GoInstall
  :GoTest
  :GoRun
  :GoPath
  :GoLint
  :GoImport package_name