Update pipeline graph styles to match mockup

Annabel Dunstone Grayrequested to merge
21604-pipeline-ui-updates into master

What does this MR do?

  • Updates CSS for pipeline graph to match mockup
  • Adds JS to dynamically change line widths based on number of builds

Screenshots (if relevant)

Screen_Shot_2016-10-04_at_2.06.24_PM

What are the relevant issue numbers?

Closes #21604 (closed)

Merge request reports