Merge branch '25735-font-size' into 'master'

Update font size of detail page header to 14px

Before:    
![Screen_Shot_2016-12-19_at_2.55.08_PM](/uploads/ff1544631ff376c3039674ac45eec696/Screen_Shot_2016-12-19_at_2.55.08_PM.png)
After:   
![Screen_Shot_2016-12-19_at_2.54.48_PM](/uploads/8a1038cc851e186eddada625b8c8de83/Screen_Shot_2016-12-19_at_2.54.48_PM.png)

Closes #25735

See merge request !8183

app/assets/stylesheets/pages/detail_page.scss

@@ -2,7 +2,6 @@
   padding: $gl-padding-top 0;
   border-bottom: 1px solid $border-color;
   color: $gl-text-color-dark;
-  font-size: 16px;
   line-height: 34px;
 
   .author {