📝 Update CHANGELOG [ci skip]

Author: mrkn

CHANGELOG.md

@@ -1,4 +1,4 @@
-# 1.0.0
+# 1.0.1
 
 - Add `mean_variance` method in Array class and Enumerable module
 - Add optimized implementation of `mean_variance` method for a Hash
@@ -9,3 +9,7 @@
     - `mean_stddev`
 - Add `sum` method in Array class and Enumerable module when Ruby < 2.4, that is almost same as introduced in Ruby 2.4
 - Add optimized implementation of `sum` method for a Range with integer ends and a Hash, that is almost same as introduced in Ruby 2.4
+
+# 1.0.0
+
+- This version was yanked due to documentation issue