Dashboard: highlight more obvious click areas on thumbnail previews
Dashboard: highlight more obvious click areas on thumbnail previews

concourse/concourse#1670

Signed-off-by: Gabriel Dumitrescu <ac98dc248ba95b80e235d49d71a9a50afc4ea93d@pivotal.io>

concourse/concourse,concourse/concourse,concourse/concourse,concourse/concourse,concourse/concourse