upgrade to 3.0.0 and update changelog

Merge branch 'master' of github.com:networknt/json-schema-validator

upgrade to 2.0.0 and update changelog

upgrade to 1.5.9 and update changelog

upgrade to 1.5.8 and update changelog

upgrade to 1.5.7 and update changelog

upgrade to 1.5.6 and update changelog

upgrade to 1.5.5 and update changelog

upgrade to 1.5.4 and update changelog

upgrade to 1.5.3 and update changelog