Added constantinople, petersburg HF blocks for mainnet and ropsten

Author: holgerd77

src/chains/mainnet.json

@@ -52,7 +52,13 @@
  },
  {
  "name": "constantinople",
- "block": null,
+ "block": 7280000,
+ "consensus": "pow",
+ "finality": null
+ },
+ {
+ "name": "petersburg",
+ "block": 7280000,
  "consensus": "pow",
  "finality": null
  }

src/chains/ropsten.json

@@ -52,7 +52,13 @@
  },
  {
  "name": "constantinople",
- "block": null,
+ "block": 4230000,
+ "consensus": "pow",
+ "finality": null
+ },
+ {
+ "name": "petersburg",
+ "block": 4939394,
  "consensus": "pow",
  "finality": null
  }