def is_changelog_format_correct?
      changelog_file = Danger::Changelog::ChangelogFile.new(filename)
      if changelog_file.exists?
        changelog_file.bad_lines.each do |line|
          markdown <<-MARKDOWN
```markdown
#{line}```
          MARKDOWN
        end
        messaging.fail("One of the lines below found in #{filename} doesn't match the [expected format](https://github.com/dblock/danger-changelog/blob/master/README.md#whats-a-correctly-formatted-changelog-file). Please make it look like the other lines, pay attention to version numbers, periods, spaces and date formats.", sticky: false) if changelog_file.bad_lines?
        messaging.fail("Please put back the `#{Danger::Changelog.config.placeholder_line.chomp}` line into #{filename}.", sticky: false) unless changelog_file.your_contribution_here? || !Danger::Changelog.config.placeholder_line?
        changelog_file.good?
      else
        messaging.fail("The #{filename} file does not exist.", sticky: false)
        false
      end
    end
def is_changelog_format_correct?
      changelog_file = Danger::Changelog::ChangelogFile.new(filename)
      if changelog_file.exists?
        changelog_file.bad_lines.each do |line|
          markdown <<-MARKDOWN
```markdown
#{line}```
          MARKDOWN
        end
        messaging.fail("One of the lines below found in #{filename} doesn't match the [expected format](https://github.com/dblock/danger-changelog/blob/master/README.md#whats-a-correctly-formatted-changelog-file). Please make it look like the other lines, pay attention to version numbers, periods, spaces and date formats.", sticky: false) if changelog_file.bad_lines?
        messaging.fail("Please put back the `#{Danger::Changelog.config.placeholder_line.chomp}` line into #{filename}.", sticky: false) unless changelog_file.your_contribution_here? || !Danger::Changelog.config.placeholder_line?
        changelog_file.good?
      else
        messaging.fail("The #{filename} file does not exist.", sticky: false)
        false
      end
    end
Is the CHANGELOG.md format correct?
 @return  [boolean]