Make pill items match their heights

app/assets/stylesheets/components/pill.scss

@@ -14,6 +14,13 @@
       See: https://www.w3.org/TR/css-flexbox-1/#flex-containers
     */
     float: left;
+    /*
+      Setting this as a flex container means the contents (1 item)
+      will fill the vertical space due to `align-items` defaulting
+      to `stretch`.
+      See: https://css-tricks.com/snippets/css/a-guide-to-flexbox/#prop-align-items
+    */
+    display: flex;
   }
 
   a,