vertically center search box

Author: jesobreira

styles/theme-base.css

@@ -182,7 +182,7 @@ textarea {
 .navbar-search {
   position: relative;
   float: left;
-  margin-top: .625rem;
+  margin-top: .770rem;
   margin-bottom: 0;
   width:100%;
   -moz-box-sizing:border-box;