Rename files containing org and htm writer

The naming `org.go` is confusing as it's not the main class of the org package

org/html_test.go

@@ -1,23 +0,0 @@
-package org
-
-import (
-	"strings"
-	"testing"
-)
-
-func TestHTMLWriter(t *testing.T) {
-	for _, path := range orgTestFiles() {
-		expected := fileString(path[:len(path)-len(".org")] + ".html")
-		reader, writer := strings.NewReader(fileString(path)), NewHTMLWriter()
-		actual, err := NewDocument().Silent().SetPath(path).Parse(reader).Write(writer)
-		if err != nil {
-			t.Errorf("%s\n got error: %s", path, err)
-			continue
-		}
-		if actual != expected {
-			t.Errorf("%s:\n%s'", path, diff(actual, expected))
-		} else {
-			t.Logf("%s: passed!", path)
-		}
-	}
-}