Style Fix Rollup

A place to track minor style fixes that need to be touched up before 2.0.0 release.

1. Graph tooltip should have higher z-index than graph legend 
<img width="303" alt="image" src="https://user-images.githubusercontent.com/21034/74358419-a18fdf00-4d7e-11ea-8082-a2c79c294cdf.png">
