Add federation logic

From sosguthorpe on Slack: 

FYI: I have merged a change into the master branch of agreements. It is based on the changes that GBV have tested for us and we believe it to be stable and, more importantly introduces proper federation logic. We haven't observed any issues in the tests as of yet but want to make you guys all aware. If you notice anything related to tenant activation, or the jobs scheduler please ask on here and feel free to @  me. If I appear to not have seen it, you can ask Ethan to kick me too!
The version is 5.3.0-SNAPSHOT.506 and has not yet been deployed on snapshot because of the build issues it's facing with Kafka ATM.