epiphany: add missing dependencies

WARNING: QA Issue: epiphany rdepends on libavahi-common but its not a
build dependency? [build-deps]
WARNING: QA Issue: epiphany rdepends on libnotify but its not a build
dependency? [build-deps]
WARNING: QA Issue: epiphany rdepends on libavahi-gobject but its not a
build dependency? [build-deps]
WARNING: QA Issue: epiphany rdepends on libavahi-client but its not a
build dependency? [build-deps]

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>