Update ChangeLog for the version 2.57b release. (#103)

* Update ChangeLog for the version 2.57b release.

* fix a typo

Author: Dor1s

docs/ChangeLog

@@ -16,6 +16,16 @@ Not sure if you should upgrade? The lowest currently recommended version
 is 2.41b. If you're stuck on an earlier release, it's strongly advisable
 to get on with the times.
 
+---------------------------
+Version 2.57b (2020-06-30):
+---------------------------
+
+  - llvm_mode and alf-clang-fast related fixes.
+
+  - Android support.
+
+  - Fixed bugs with stability calculate and testcase calibration.
+
 ---------------------------
 Version 2.56b (2019-09-26):
 ---------------------------