Add hover effect to bubble chart nodes
Add hover effect to bubble chart nodes

Change-Id: Id599d1cc3eb93b96b1a546b22a0a1b04b443df6a
Reviewed-on: https://gerrit.causes.com/26620
Reviewed-by: Greg Hurrell <79e2475f81a6317276bf7cbb3958b20d289b78df@causes.com>
Tested-by: Greg Hurrell <79e2475f81a6317276bf7cbb3958b20d289b78df@causes.com>

causes/twigg,causes/twigg