In order to be able to test resource server we need to be able
to share a network between our docker compose stack. Let's add
a network to make it work.
Set `sslRequired` to `none` for all realms in the keycloak dev service.
By default this settings is set to `external` and only local IPs are granted
to access to the server without SSL. But sometimes, with docker (desktop?)
it appears the network configuration may keycloak to consider the accessing
ip as not local.
We also took opportunity of this change to use the latest keycloak image version
Resolve#291
Nathan Vasse