Compatibility with React 16.7, aka Hooks

Breaking Changes

• removed loadable-components dependency since new version compatable with React 16.7 requires Webpack and Rogue is independent of any build setup (plus, React.lazy and Suspense makes it less necessary to have this built-in)
• removed @roguejs/cli package. it was never finished (partly because we were waiting for Parcel to progress, partly due to time constraints) and there's already great ssr built tools like Razzle that solve this decently enough

Other than that, just simplified logic and added basic tests to app middleware. :)