CHANGELOG.md in benchmark_driver-0.15.6 vs CHANGELOG.md in benchmark_driver-0.15.7

- old
+ new

@@ -1,4 +1,8 @@
+# v0.15.7
+
+- Add `median` to --repeat-result options
+
 # v0.15.6
 
 - Fix new keyword argument warnings for the latest Ruby 2.7
 
 # v0.15.5