Style source
I am attempting to style a column based on another column's data, for example:

``` python
import pandas as pd

now = pd.datetime.now()
rng = now + pd.timedelta_range("1D","10D",freq='D')

df = pd.DataFrame(rng,columns=["ExactDate"])

df['Display Date'] = df['ExactDate'].dt.strftime("%m-%Y")

style = df.style.bar(subset='Display Date', source = rng)

html = style.render()

print html
```

Gives: 
![image](https://cloud.githubusercontent.com/assets/9845637/11811135/7a8fd588-a32b-11e5-8d0b-03c73c417040.png)
