Issue title: Clear documentation on installing go
 Issue body: Explain how to set up your go environment properly ($GOPATH, $GOBIN, $PATH) and add a reminder to the docs after the installing go section.
 Comments: 
 Comment 0: It might be sufficient to just say "Remember to set the $GOBIN and $GOPATH environment variables", since how those work is documented by golangs docs, and how to do it is documented by golang and in our install scripts. 
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