message: Handle empty frontmatter gracefully
diff: @@ -177,10 +177,7 @@ impl Document {
  let yaml_result = try!(YamlLoader::load_from_str(attribute_split));
  - if yaml_result.is_empty() {
  - return Err(format!("Incorrect front matter format in {:?}", file_path).into());
  - }
  -
  + if !yaml_result.is_empty() {
  let yaml_attributes = try!(yaml_result[0]
  .as_hash()
  .ok_or_else(|| format!("Incorrect front matter format in {:?}", file_path)));
  @@ -194,6 +191,8 @@ impl Document {
  }
  }
  + }
  +
  content_split
  } else {
  content
  