Reduce padding of mr widget mini graph

app/assets/stylesheets/pages/merge_requests.scss

@@ -125,6 +125,12 @@
       line-height: 16px;
     }
+    @media (min-width: $screen-sm-min) {
+      .stage-cell {
+        padding: 0 4px;
+      }
+    }
+
     @media (max-width: $screen-xs-max) {
       order: 1;
       margin-top: $gl-padding-top;