Update CHANGELOG.md

Author: chaoxinhu

CHANGELOG.md

@@ -1,3 +1,20 @@
+### V1.2.0 (2019-05-10)
+* 新增：
+1. SpecificIssuer数据合约及逻辑合约，用于在链上登记特定类型issuer角色
+2. CPT新增注册接口，允许在注册时指定CPT ID
+
+* 修正：
+1. 大幅度提升了Committee及AuthorityIssuer相关实现的性能
+2. AuthorityIssuer的机构名现在是唯一的
+
+* Added:
+1. Smart Contract for Specific Issuer management, allowing registering specific issuer roles on blockchain.
+2. New interfaces to register CPT with a specified CPT ID.
+
+* Bugfixes:
+1. Significantly improved the performance of related implementations in Committee and AuthorityIssuer.
+2. Authority Issuer names are now unique.
+
 ### V1.1.0 (2019-01-30)
 
 * 新增：