Merge branch 'issue-board-label-spacing' into 'master'

Increased vertical alignment of labels for issues in lists

## What does this MR do?

Increases the vertical alignment between labels on issues in issue boards lists.

## Screenshots (if relevant)

![Screen_Shot_2016-08-19_at_16.05.31](/uploads/4edc0fa520d1a0bf692d42d5f99ce4d7/Screen_Shot_2016-08-19_at_16.05.31.png)

See merge request !5902

app/assets/stylesheets/pages/boards.scss

@@ -315,6 +315,7 @@
 
 .card-footer {
   margin-top: 5px;
+  line-height: 25px;
 
   .label {
     margin-right: 4px;