fix(BEMNaming): remove `BEMNaming` filed
fix(BEMNaming): remove `BEMNaming` filed

Before BEMNaming class it used to create instance:

```js
import bemNaming from 'bemNaming';

const BEMNaming = bemNaming.BEMNaming;
const myNaming = new BEMNaming({ elem: '__', mod: '--' });
```

Now it is necessary use `bemNaming` function:

```js
import bemNaming from 'bemNaming';

const myNaming = bemNaming({ elem: '__', mod: '--' });
```

bem/bem-naming,bem-sdk/bem-naming