DOC: Data links in Pandas API Reference are broken 404
#### Location of the documentation

https://pandas.pydata.org/docs/reference/api/pandas.plotting.parallel_coordinates.html
...probably many examples in other sections

#### Documentation problem

Results in 404 not found error
df = pd.read_csv('https://raw.github.com/pandas-dev/pandas/master'
                    '/pandas/tests/data/csv/iris.csv')

#### Suggested fix for documentation

The GitHub site should be "raw.githubusercontent.com" 
