Bumped version to v1.3.1, added CHANGELOG entry, updated Istanbul sec…

…tion in README

CHANGELOG.md

@@ -6,6 +6,18 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 (modification: no type change headlines) and this project adheres to
 [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [1.3.1] - 2019-08-08
+
+Added missing **Istanbul** gas costs for:
+
+- ChainID opcode (EIP-1344, as base param in `hardforks/chainstart.json`)
+- Blake2b precompile (EIP-2129/152)
+- Calldata gas cost reduction (EIP-2028)
+
+See PR [#58](https://github.com/ethereumjs/ethereumjs-common/pull/58).
+
+[1.3.1]: https://github.com/ethereumjs/ethereumjs-common/compare/v1.3.0...v1.3.1
+
 ## [1.3.0] - 2019-06-18
 
 - Add a static factory method `Custom.forCustomChain` to make working with

README.md

@@ -85,7 +85,11 @@ associated EIP pages.
 Supported EIPs in the library:
 
 - [EIP-1108](https://eips.ethereum.org/EIPS/eip-1108) `alt_bn128` precompile
-  gas cost reductions (HF candidate, `DRAFT` status)
+  gas cost reductions (`DRAFT` status)
+- [EIP-1344](https://eips.ethereum.org/EIPS/eip-1344) ChainID opcode
+  (as `gasPrices` -> `base` parameter in `hardforks/chainstart.json`)
+- [EIP-2129/152](https://github.com/ethereum/EIPs/pull/2129) Blake2b precompile
+- [EIP-2028](https://eips.ethereum.org/EIPS/eip-2028) Calldata gas cost reduction
 
 ## Parameter Access
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ethereumjs-common",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "Resources common to all Ethereum implementations",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",