update release date

Author: jleechung

README.Rmd

@@ -129,7 +129,7 @@ Most human genes have multiple promoters that control the expression of distinct
 
 **Release 0.99.0** 
 
-Release date: 4th August 2020
+Release date: 21st August 2020
 
 Changes in version 0.99.0:
 

README.md

@@ -165,7 +165,7 @@ is described in detail
 
 **Release 0.99.0**
 
-Release date: 4th August 2020
+Release date: 21st August 2020
 
 Changes in version 0.99.0: