Add tests

[znck]

Possible testing approach:

• [ ] Create SSR website with Nuxt
• [ ] Export static build with nuxt generate
• [ ] Use cypress to test hydration

[Timkor]

Currently it fails in Nuxt dev mode.

import LazyHydrate from 'lazy-hydration';

const Hydrate = process.env.NODE_ENV === 'production' ? LazyHydrate : {
    functional: true,
    render(c, {slots}) {
        return slots().default;
    }
}

export default Hydrate;

Wrapping it like this did the trick. Any idea?