Move restbase config to regex.yaml

This targets the restbase and cassandra config to the test hosts, and should
work with the new hiera setup as per
https://gerrit.wikimedia.org/r/#/c/174694/ and
https://wikitech.wikimedia.org/wiki/Puppet_Hiera#Practical_example.

Bug: T1228

Change-Id: I8d157b5757df898e16172ec88e657edf6c132a9c