TESTNET_DEFAULTS
Testnet default parameters, matching the ledger's initial dust parameters.
nightDustRatio= 5,000,000,000 (5 Dust per Night).generationDecayRate= 8,267 (generation time of roughly one week).
Reference constants: 1 Dust = 1,000,000,000,000,000 Specks (10^15) and 1 NIGHT = 1,000,000 Stars (10^6).