Merge branch 'release/0.0.30' into develop
readme: improve readability
src: improve readability
src: added instance method 'trace()'
test: added instance method 'trace()' testings
lint: added some files for linting pass
readme: added instance method 'trace()' api
Merge branch 'feature/instance_method_trace' into develop
npm: 0.0.30 -> 0.0.31
Merge branch 'release/0.0.31'