Vanchi/simplify persistence n tests

@zendesk/zendesk-radar 

This has a lot of simplifications:
1. Persistence has connect/disconnect so that we can wait when sentinel connections are ready
2. radar server terminate now has a callback which works
3. resource subscribes are also async. (Destroys are not, since no one is waiting).
4. tests are slightly simpler. (client generation code moved).
5. tests/configuration.js file which will now start seeing sentinel configurations
6. FIX: when auth fails, we should not subscribe to the resource.