v5.7.0

What's Changed

• Add find, find_index, has, and reject filters to arrays by @karreiro in #1869
• Add the "Releasing" section to CONTRIBUTING.md by @karreiro in #1891
• Implement logic for stringify Hashes to keep compat with 3.4 by @ianks in #1892
• Allow for custom < Hash classes to override #to_s by @ianks in #1896
• Use Liquid::Utils.to_s for join filter by @ianks in #1897
• Ensure we use InputIterator#each when in join filter by @ianks in #1898
• Bump to 5.7.0 by @karreiro in #1894

Full Changelog: v5.6.4...v5.7.0