[*]: update the changelog

[*]: optimize php-docs v2

[*]: optimize php-docs

-> use html-tags for comments :)

[*]: fix php-docs

[~]: refactoring methods with "__"-prefix into "_" (no breaking changes)

[+]: add more tests v3

[+]: use "assertSame" instead of "assertEquals"

[~]: move "php-coveralls" into ".travis.yml"

[~]: spilt tests v2

[-]: use "git tags"

Update composer.json v2