Change 'import Syncano' to 'import Server' in the cheatsheet docs

The doc first instructs to do:

```import Syncano from ‘syncano-server’

export default (ctx) => {
  const {data} = new Syncano(ctx)

  data.posts
    .create({title: 'Lorem ipsum'})
    .then(post => {
      console.log(post.title)
    })
}
```

And then continues with:

```const {response} = new Server(ctx)```

This should be unified