fix(css): minor style fix

public/sass/components/_dropdown.scss

@@ -8,10 +8,7 @@
 .dropdown {
   position: relative;
 }
-.dropdown-toggle {
-  // The caret makes the toggle a bit too tall in IE7
-  margin-bottom: -3px;
-}
+
 .dropdown-toggle:active,
 .open .dropdown-toggle {
   outline: 0;