Cannot compile ttop.go just like other examples which import "extra" package
go run ttop.go
ttop.go:23:2: cannot find package "github.com/gizak/termui/extra" in any of:
/usr/local/Cellar/go/1.6/libexec/src/github.com/gizak/termui/extra (from $GOROOT)
/<$HOME>/go/src/github.com/gizak/termui/extra (from $GOPATH)
Cannot compile ttop.go just like other examples which import "extra" package