title: cannot download, $GOPATH not set
body: <p>I want to install json2csv using <code>go get github.com/jehiah/json2csv</code> but I receive this error:</p>
  
  <pre><code>package github.com/jehiah/json2csv: cannot download, $GOPATH not set. For more details see: go help go path
  </code></pre>
  
  <p>Any help on how to fix this on MacOS?</p>