Code sample on pandas.Series.eq page is for pandas.Series.add
#### Problem description

The code sample shown in the "Examples" section on the [doc page for pandas.Series.eq](https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.eq.html) appears to be for pandas.Series.add instead of eq.

![image](https://user-images.githubusercontent.com/14127094/59866977-c774f900-9341-11e9-9d15-6925da53b7c3.png)
