v5.10.0

What's Changed

• ci: exclude tests/ from Codacy analysis by @elminson in #392
• chore: remove dead .travis.yml by @elminson in #393
• Add .gitattributes by @klimov-paul in #253
• chore: modernize .gitattributes export-ignore list by @elminson in #394
• ci: align phpcs.xml with the codebase's concatenation style by @elminson in #396
• Clarify export options by @xwiz in #195
• Handle duplicate and empty header names on import by @elminson in #395
• docs: low-memory streaming imports for large files (#162) by @elminson in #391
• Accept any Traversable as export data by @elminson in #397
• fix: write placeholder row for empty sheets in multi-sheet exports by @dannyyol in #401
• Fail clearly when exporting multiple sheets to a single-sheet format (#244) by @elminson in #398
• Make string vs number export configurable (#193) by @elminson in #400

New Contributors

• @klimov-paul made their first contribution in #253
• @xwiz made their first contribution in #195

Full Changelog: v5.9.0...v5.10.0