def associations
      {
        css:    ['css'],
        scss:   ['scss', 'sass'],
        js:     ['js'],
        ruby:   ['rb', 'Gemfile', 'lock', 'yml', 'Rakefile', 'ru', 'rdoc', 'rake', 'Capfile', 'jbuilder'],
        rails:  ['slim', 'haml', 'jbuilder', 'erb'],
        images: ['png', 'jpg', 'jpeg', 'gif'],
        static: ['pdf', 'txt', 'doc', 'docx', 'csv', 'xls', 'xlsx'],
        markup: ['html', 'xml', 'xhtml'],
        markdown: ['md', 'markdown', 'mdown'],
        php:    ['php', 'ini']
      }
    end
def associations
      {
        css:    ['css'],
        scss:   ['scss', 'sass'],
        js:     ['js'],
        ruby:   ['rb', 'Gemfile', 'lock', 'yml', 'Rakefile', 'ru', 'rdoc', 'rake', 'Capfile', 'jbuilder'],
        rails:  ['slim', 'haml', 'jbuilder', 'erb'],
        images: ['png', 'jpg', 'jpeg', 'gif'],
        static: ['pdf', 'txt', 'doc', 'docx', 'csv', 'xls', 'xlsx'],
        markup: ['html', 'xml', 'xhtml'],
        markdown: ['md', 'markdown', 'mdown'],
        php:    ['php', 'ini']
      }
    end
Define associations to linters based on file extension
 @return [Hash] linters and extension arrays