Remove overflow on content, closes elixir-lang#972

Author: José Valim

assets/less/layout.less

@@ -38,7 +38,6 @@ body {
 .content {
   width: 100%;
   padding-left: 300px;
-  overflow-y: auto;
   -webkit-overflow-scrolling: touch;
   height: 100%;
   position: relative;