title: Package name containing hyphen
body: <p>I am having some trouble understanding that why my code complains when I have hyphen in package.
  e.g. if I have a package name foo-bar and I declare that package name</p>
  <pre><code>package foo-bar
  
  foo-bar/config.go:1:13: expected ';', found '-'
  </code></pre>
  <p>Then why does the Go compiler complain? Does it mean we should not use hyphens in go package names?</p>
  <p>Since there are many repo that has use hyphen in package name, am I doing something wrong?</p>