v0.6.6

What's Changed

• update readme by @eeliu in #661
• Update Readme-CN.md by @Evelyn0927 in #664
• Update Readme-KR.md by @Evelyn0927 in #663
• Update Readme-KR.md by @Evelyn0927 in #665
• report ext ver in phpinfo by @remicollet in #666
• Fix build warnings by @remicollet in #667
• release collector-agent binary by @eeliu in #668
• fix arm failed by @eeliu in #669

Full Changelog: v0.6.5...v0.6.6