Add Bounces & Bounce Rate to Discover

[#1]

Please add the Bounces & Bounce Rate to Discover as well. Currently it's only showing in SC15

[#2]

And be able to create a segment based on it

[#3]

Both of these requests have been implemented, actually. Bounces and Bounce Rate are now available as metrics in ad hoc analysis, and a Bounce Rate segment is created simply by doing Visits (or Visitors) where Visit Depth = 1.