Add bolditalic styling for RST (#603)
Add bolditalic styling for RST (#603)

RST cannot produce bold+italic by nesting markup. We can
workaround this by defining a bolditalic role that translates
to an HTML class, then style the class as needed.

This patch defines the styling for the bolditalic class.

Partial: rackerlabs/docs-workstream#123
meker12/nexus-control,rackerlabs/nexus-control,rackerlabs/nexus-control,meker12/nexus-control,meker12/nexus-control,rackerlabs/nexus-control