Generalize teaser style.

services/web/public/stylesheets/app/editor.less

@@ -413,11 +413,13 @@
 	}
 }
 
+.teaser-title,
 .dropbox-teaser-title {
 	margin-top: 0;
 	text-align: center;
 }
 
+.teaser-img,
 .dropbox-teaser-img {
 	.img-responsive;
 	margin-bottom: 5px;