title: Prevent "<no value>" being inserted by golang text/template library
body: <p>Go places <code>&lt;no value&gt;</code> as the result of a the template expansion
  when no value is present for a particular template parameter.</p>
  
  <p>Is there any way to prevent this?
  All I can think of right now is to insert an empty version of "AppVersion"
  into the data map</p>
  
  <p>e.g.</p>
  
  <pre><code>package main
  
  import (
      "text/template"
      "log"
      "bytes"
      "fmt"
  )
  
  func main() {
      data := make(map[string]string)
      //data["AppVersion"] = "Octane_3.0"
  
      text := "APP_VERSION={{.AppVersion}}"
      tmpl, err := template.New("").Parse(text)
      if err != nil {
          log.Fatal(err)
      }
  
      var b bytes.Buffer
      err = tmpl.Execute(&amp;b, data)
      if err != nil {
          fmt.Println("template.Execute failed", err)
      }
  
      fmt.Println("Template text:", text)
      fmt.Println("Expanded:", b.String())
  }
  </code></pre>
  
  <p><a href="https://play.golang.org/p/OuLhcHOCsWJ" rel="noreferrer">https://play.golang.org/p/OuLhcHOCsWJ</a></p>