#1547 update changelog

Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 Please mark all change in change log and use the issue from GitHub
 
-# Milvus 0.7.0 (TBD)
+# Milvus 0.7.0 (2020-03-11)
 
 ## Bug
 -   \#715 Milvus crash when searching and building index simultaneously using SQ8H