Center button text.

dist/ratchet.css

@@ -573,7 +573,7 @@ select {
 [class*="button"] {
   position: relative;
   display: inline-block;
-  padding: 5px 10px 6px;
+  padding: 5px 10px 7px;
   margin: 0;
   font-weight: 400;
   line-height: 1;

lib/sass/buttons.scss

@@ -5,7 +5,7 @@
 [class*="button"] {
   position: relative;
   display: inline-block;
-  padding: 5px 10px 6px;
+  padding: 5px 10px 7px;
   margin: 0;
   font-weight: $font-weight-light;
   line-height: 1;