Version 9.0.0

• Using Yarn (#16).
• Updated dependencies.
• Upgraded to Webpack v2 (#17). This required config changes.
• Reconfigured Babel to use babel-preset-env (#18). By not unnecessarily transpiling language features that run natively in the browsers we support the bundle JS shrinks from ~19kb to ~15kb.
• Moved Browserslist config into package.json.
• New browser support. The new Browserslist query doesn't cherry-pick and uses Australian data. This drops support for Safari v8. A localized example avoids the global stats that are skewed by developing countries that use older browsers.
• Documented in the readme the level of support as a linked Browserslist query.
• Readme version badge now dynamically tracks the latest release on Github (#19).
• Misc. readme and documentation improvements including a better link explaining SVG icons and cleaner table markdown.
• Small example CSS simplification relating to selection.