Bumped version to v1.2.0, added CHANGELOG entry

Author: holgerd77

CHANGELOG.md

@@ -6,6 +6,21 @@ 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).
 
+## [1.2.0] - 2019-05-27
+
+**DRAFT Istanbul Hardfork Support**
+
+Draft support for the upcoming `Istanbul` hardfork planned for October 2019,
+use `istanbul` as constructor `hardfork` parameter to activate. Parameters
+relevant to new EIPs accepted for the HF will be added along subsequent `1.2.x`
+releases, the finalized HF version will be released along a subsequent `1.x.0`
+release (likely `1.3.0`).
+
+See new `hardforks/istanbul.json` file as well as PR
+[#51](https://github.com/ethereumjs/ethereumjs-common/pull/51).
+
+[1.2.0]: https://github.com/ethereumjs/ethereumjs-common/compare/v1.1.0...v1.2.0
+
 ## [1.1.0] - 2019-02-04
 
 **Petersburg Hardfork Support**

README.md

@@ -73,6 +73,7 @@ library supported:
 - `byzantium`
 - `constantinople`
 - `petersburg` (aka `constantinopleFix`, apply together with `constantinople`)
+- `istanbul` (`DRAFT`)
 
 For hardfork-specific parameter access with the `param()` and `paramByBlock()` functions
 you can use the following `topics`:

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ethereumjs-common",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "Resources common to all Ethereum implementations",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",