Prepare for release v0.8a1

Signed-off-by: Hiroshi Miura <[email protected]>

Author: miurahr

CHANGELOG.rst

@@ -17,13 +17,9 @@ Added
 Changed
 -------
 
-* Allow path search for 7z (#96)
-
 Fixed
 -----
 
-* Detect exception on each download and extraction threads.
-
 Deprecated
 ----------
 
@@ -33,6 +29,23 @@ Removed
 Security
 --------
 
+
+`v0.8a1`_ (28, Feb., 2020)
+==========================
+
+Changed
+-------
+
+* Allow path search for 7z (#96)
+* Simplify multithreading using concurrent.futures.ThreadPoolExecutor().
+
+Fixed
+-----
+
+* Detect exception on each download and extraction threads.
+* Race condition error happend on py7zr. require py7zr>=0.5.3.(#97)
+
+
 `v0.7.4`_ (15, Feb., 2020)
 ==========================