使用brew安装go后在哪里设置GOPATH?

I installed Go on my ubuntu 14.04 using Linux brew and then I have set GOPATH to $HOME/go. But after that i tried to install goauth package for go using go get command but still my code is not importing goauth package. After going through the error I decided to check the GOPATH. It is properly set but the goauth package is not getting installed in $HOME/go/src/code.google.com/p. Please suggest me a work around. Here is the error that I am getting.

dummy.go:5:8: cannot find package "code.google.com/p/goauth2/oauth" in any of:
    /home/avinash/.linuxbrew/Cellar/go/1.4.2/libexec/src/code.google.com/p/goauth2/oauth (from $GOROOT)
    /home/avinash/go/src/code.google.com/p/goauth2/oauth (from $GOPATH)
go/src/github.com/google/go-github/github/github.go:22:2: cannot find package "github.com/google/go-querystring/query" in any of:
    /home/avinash/.linuxbrew/Cellar/go/1.4.2/libexec/src/github.com/google/go-querystring/query (from $GOROOT)
    /home/avinash/go/src/github.com/google/go-querystring/query (from $GOPATH)