Lab 2 Notes AttributeError: Unknown property color_cycle

While running, this cell:

```
diamonds['price'].plot(kind='kde', color = 'black')
plt.title('Distribution of Price')
```

from [this notebook](https://github.com/cs109/2014/blob/master/labs/Lab2_Notes.ipynb).

I am getting:

```
AttributeError: Unknown property color_cycle
```

Kindly help, I am taking the 2014 archived course.
