Added haml-lint and fix warnings (#2773)

* add haml_lint to Gemfile

* add .haml-lint.yml

* fix warnings of haml_lint

app/views/admin/reports/_report.html.haml

@@ -6,15 +6,15 @@
   %td.reporter
     = link_to report.account.acct, admin_account_path(report.account.id)
   %td.comment
-    %span{title: report.comment}
+    %span{ title: report.comment }
       = truncate(report.comment, length: 30, separator: ' ')
   %td.stats
     - unless report.statuses.empty?
-      %span{title: t('admin.accounts.statuses')}
+      %span{ title: t('admin.accounts.statuses') }
         = fa_icon('comment')
         = report.statuses.count
     - unless report.media_attachments.empty?
-      %span{title: t('admin.accounts.media_attachments')}
+      %span{ title: t('admin.accounts.media_attachments') }
         = fa_icon('camera')
         = report.media_attachments.count
   %td