Center build stage columns in pipeline overview

CHANGELOG

@@ -13,6 +13,7 @@ v 8.12.0 (unreleased)
   - Add `web_url` field to issue, merge request, and snippet API objects (Ben Boeckel)
   - Set path for all JavaScript cookies to honor GitLab's subdirectory setting !5627 (Mike Greiling)
   - Fix bug where pagination is still displayed despite all todos marked as done (ClemMakesApps)
+  - Center build stage columns in pipeline overview (ClemMakesApps)
   - Shorten task status phrase (ClemMakesApps)
   - Add hover color to emoji icon (ClemMakesApps)
   - Fix branches page dropdown sort alignment (ClemMakesApps)

app/assets/stylesheets/pages/pipelines.scss

@@ -2,6 +2,7 @@
   .stage {
     max-width: 90px;
     width: 90px;
+    text-align: center;
     overflow: hidden;
     text-overflow: ellipsis;
     white-space: nowrap;
@@ -146,6 +147,7 @@
   }
 
   .stage-cell {
+    text-align: center;
 
     svg {
       height: 18px;
@@ -153,10 +155,6 @@
       vertical-align: middle;
       overflow: visible;
     }
-
-    .light {
-      width: 3px;
-    }
   }
 
   .duration,