Make some methods in Dirty module public

[andrykonchin]

Make the following existing Dirty methods public:

• clear_changes_information
• changes_applied
• clear_attribute_changes

These methods are public in Rails' ActiveModel - https://api.rubyonrails.org/classes/ActiveModel/Dirty.html

[codecov]

Codecov Report

Merging #627 (a5705a1) into master (13ee680) will decrease coverage by 0.00%.
The diff coverage is 97.50%.

❗ Current head a5705a1 differs from pull request most recent head 3ab00ba. Consider uploading reports for the commit 3ab00ba to get more accurate results

@@            Coverage Diff             @@
##           master     #627      +/-   ##
==========================================
- Coverage   90.17%   90.17%   -0.01%     
==========================================
  Files          60       60              
  Lines        3054     3053       -1     
==========================================
- Hits         2754     2753       -1     
  Misses        300      300              

Impacted Files	Coverage Δ
lib/dynamoid/dirty.rb	96.38% <97.50%> (-0.05%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[github-actions]

Package	Line Rate	Health
dynamoid	90%	➖
Summary	90% (2753 / 3053)	➖

Minimum allowed line rate is 90%