title: GOPATH not found error from the Gofmt plugin within SublimeText
body: <p>I keep getting this error within Sublime Text, after installing the <code>gofmt</code> package:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/Users/abrahma/Library/Application Support/Sublime Text 3/Installed Packages/Gofmt.sublime-package/gofmt.py", line 257, in run_formatter
      formatter = Formatter(view)
    File "/Users/abrahma/Library/Application Support/Sublime Text 3/Installed Packages/Gofmt.sublime-package/gofmt.py", line 166, in __init__
      self.cmds = [Command(cmd, self.view, self.window) for cmd in cmds]
    File "/Users/abrahma/Library/Application Support/Sublime Text 3/Installed Packages/Gofmt.sublime-package/gofmt.py", line 166, in &lt;listcomp&gt;
      self.cmds = [Command(cmd, self.view, self.window) for cmd in cmds]
    File "/Users/abrahma/Library/Application Support/Sublime Text 3/Installed Packages/Gofmt.sublime-package/gofmt.py", line 77, in __init__
      self.window)
    File "/Users/abrahma/Library/Application Support/Sublime Text 3/Packages/golangconfig/all/golangconfig.py", line 227, in subprocess_info
      raise exception
  golangconfig.EnvVarError: The following environment variable is currently unset: GOPATH
  </code></pre>
  
  <p>My `` file has the following:</p>
  
  <pre><code>    "env" : {
          "GOPATH" : "/Users/abrahma/git/go",
          "GOROOT" : "/usr/local/Cellar/go/1.12.7/libexec",
      }
  </code></pre>
  
  <p>(which matches the output of <code>go env</code> on my terminal)</p>
  
  <p>I also have a <code>golang.sublime-settings</code> file with the following:</p>
  
  <pre><code>{
      "env" : {
          "GOPATH" : "/Users/abrahma/git/go",
          "GOROOT" : "/usr/local/Cellar/go/1.12.7/libexec",
      }
  }
  </code></pre>
  
  <p>So, for some reason, the <code>GOPATH</code> above clearly isn't getting picked up, any ideas why?</p>