Broken Url for Setuptools
#### Broken Url for Setuptools in docs

```python
Setuptools link points incorrectly to http://pythonhosted.org/setuptools
```
#### Problem description
Currently in http://pandas-docs.github.io/pandas-docs-travis/install.html#recommended-dependencies the link to Setuptools in the dependencies section redirects to 
http://pythonhosted.org/setuptools. This link is out of date, use correct url of https://setuptools.readthedocs.io/en/latest/
