`is_emoji("☕️") is False`

Tested on version 2.15.0:
```python
import emoji
emoji.__version__
# Out[3]: '2.15.0'
emoji.is_emoji("☕️")
# Out[4]: False
emoji.is_emoji("☕️"[0])
# Out[5]: True
```

Particularly there's a single unicode character emoji here (which is True) and a double character which is False.