Merge pull request #3842 from alienlebarge/2.1.0-wip

<img /> tag with `height` attr are not responsive

less/reset.less

@@ -78,6 +78,7 @@ sub {
 
 img {
   max-width: 100%; // Make images inherently responsive
+  height: auto; // Make images inherently responsive
   vertical-align: middle;
   border: 0;
   -ms-interpolation-mode: bicubic;