Metrics collection

This script will collect a DC's total desired and actual when run. 

**TODO**:
- [x] Collect pending also
- [ ] Tests
- [ ] Dump the data to Cloud metrics
Non-blocking - wondering if we wanted to make that a set so it has unique items?  No real issue with things getting sent twice though  - it probably produces the same dictionary, but I don't quite remember if that's the case.