add license metadata to package.json
add license metadata to package.json

vxvinh1511/TinyColor,bgrins/TinyColor,mwcz/TinyColor,dabassett/TinyColor,bgrins/TinyColor,GerHobbelt/TinyColor,pandabamboo90/TinyColor,dabassett/TinyColor,weepy/TinyColor,pandabamboo90/TinyColor,weepy/TinyColor,vxvinh1511/TinyColor,mwcz/TinyColor,GerHobbelt/TinyColor