docs(readme): add Greenkeeper badge
docs(readme): add Greenkeeper badge
bitwiseman/js-beautify,bitwiseman/js-beautify,bitwiseman/js-beautify,beautify-web/js-beautify,beautify-web/js-beautify,bitwiseman/js-beautify,beautify-web/js-beautify,beautify-web/js-beautify