Manual play not working

Hi there,

I am having a problem getting the manual play to work.

I get the board to render, but when I click on a column it just says "processing..." and nothing ever happens.

Here's the code:
```
from kaggle_environments import evaluate, make, utils
env = make("connectx", debug=True)
env.play([None, "negamax"], width=800, height=600)
```

I have tried using "random" instead of "negamax" and I have also tried switching to second player, but nothing works.

Here are the versions I am using.
```
Python 3.7.4
kaggle-environments 1.0.13
jupyterlab 2.1.4
ipython 7.13.0
```

Thank you,
Marshall

Reproduce the issue with kaggle_environments 1.0.13 in JupyterLab using make("connectx", debug=True) and env.play([None, "negamax"], width=800, height=600). Start at the env.play entry point and compare behavior with the reported player and agent variations. Done means clicking a column completes the manual play instead of remaining on "processing...".

Written by the indexing model from the issue text.