Homebrew test block fails for 0.3.6

[ilovezfs]

ref Homebrew/homebrew-core#22250

==> brew test armor --verbose
==> FAILED
Testing armor
/usr/bin/sandbox-exec -f /tmp/homebrew20171230-5697-xr5sjw.sb /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby -W0 -I /usr/local/Homebrew/Library/Homebrew -- /usr/local/Homebrew/Library/Homebrew/test.rb /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/armor.rb --verbose

   ___                     
  / _ | ______ _  ___  ____
 / __ |/ __/  ' \/ _ \/ __/
/_/ |_/_/ /_/_/_/\___/_/    v0.3.6

Uncomplicated, modern HTTP server
https://armor.labstack.com
________________________O/_______
                        O\
⇨ http server started on :8080
⇨ http server started on [::]:8080
==> curl -sI http://localhost:8080
{"time":"2017-12-30T07:57:23.900908Z","level":"ERROR","prefix":"armor","file":"echo.go","line":"285","message":"code=404, message=Not Found"}
{"time":"2017-12-30T07:57:23.901203Z","id":"","remote_ip":"::1","host":"localhost:8080","method":"HEAD","uri":"/","status":404, "latency":392335,"latency_human":"392.335µs","bytes_in":0,"bytes_out":0}
Error: armor: failed
</200 OK/m> expected to be =~
<"HTTP/1.1 404 Not Found\r\nServer: armor/0.3.6\r\nDate: Sat, 30 Dec 2017 07:57:23 GMT\r\nContent-Type: text/plain; charset=utf-8\r\n\r\n">.

The test runs

  test do
    begin
      pid = fork do
        exec "#{bin}/armor"
      end
      sleep 1
      output = shell_output("curl -sI http://localhost:8080")
      assert_match /200 OK/m, output
    ensure
      Process.kill("HUP", pid)
    end
  end

[ilovezfs]

Thanks for the fix @vishr!