Merge branch '23346-pipeline-buttons-cutoff' into 'master'

Smaller min-width for MR pipeline table

## What does this MR do?
Nests class under `.tab-pane` to make sure buttons don't get cut off

## Screenshots (if relevant)
![Screen_Shot_2016-10-14_at_11.00.02_AM](/uploads/6e19e0375721f2cb58223c2e7ed89308/Screen_Shot_2016-10-14_at_11.00.02_AM.png)

## What are the relevant issue numbers?
Closes #23346

See merge request !6893

app/assets/stylesheets/pages/pipelines.scss

@@ -643,6 +643,10 @@
 
   &.pipelines {
 
+    .ci-table {
+      min-width: 900px;
+    }
+
     .content-list.pipelines {
       overflow: auto;
     }