use active_support/core_ext/hash

Replace this text with a summary of the changes in your PR. The more detailed you are, the better.

Before submitting the PR make sure the following are checked:

[ ] The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
[ ] Wrote good commit messages.
[ ] Commit message starts with [Fix #issue-number] (if the related issue exists).
[ ] Feature branch is up-to-date with master (if not - rebase it).
[ ] Squashed related commits together.
[ ] Added tests.
[ ] Added an entry to the changelog if the new code introduces user-observable changes. See changelog entry format for details.

toptal / chewy