Bugfixes and upgrade React version to 17.0.0

Changes:

• React upgraded to 17.0.0
• Upgrade other packages
• Fixed security deps warnings
• React legacy method now prefixed with UNSAFE
• Added Blue color for hair
• Fix SVG ids not unique so multiple avataaars on the same page will be broken issue

Adding Skin comp to Piece comp and minor code updates

Thanks to @scrumptiousdev for adding Skin comp to Piece comp and minor code updates

Add showcase component

Thanks @bradrisse for contributing showcase component