As a developer, I would like CSS Builder to add a timestamp to my css imports

• Type: Story
• Status: Closed
• Priority: Trivial
• Resolution: Completed
• Affects Version/s: None
• Fix Version/s: 7.0.X EE, 7.1.X, Master
• Component/s: Dev Tools, Frontend Infrastructure, Themes Infrastructure
• Labels: None
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed

Add an option to append a timestamp to a css import i.e. @import url("font-awesome.css"); => @import url("font-awesome.css?t=12343546457");

This will prevent portal from caching the files during deployment but shouldn't be an issue during production as the timestamps won't be changing.