Add Go installation

[josephmilla]

It would be nice to have Go included in this package

[josephmilla]

@donnemartin will create a PR for this over the weekend

[donnemartin]

Hi @josephmilla, I'm not sure if this is really a great fit for the current iteration of dev-setup.

You're encouraged to fork and maintain your own customized setup.

[jpwalsh1]

If people are looking for a go install, I've added it to my fork but here is the code to share.

brew install golang
GOPATH='export PATH="/usr/local/opt/go/libexec/bin:$PATH"'
grep -q "$GOPATH" ~/.path || echo "$GOPATH" >> ~/.path