Get CI to run dbus mock tests

[jkarni]

The mock tests require DBus. They additionally require that it run with a modified config to give the user permissions to create org.bluez.Mock. However, due to a bug in DBus, reloading the config does not work. Instead the recommended path is rebooting.

Rebooting obviously presents problems on CI. It would seem that given that dbus is not at first installed, we could setup the config files first so that once it is installed it's already using them, but I haven't had luck with this yet.

C.f. test/Mock/dbus-permissions.sh