DOC: Correctly redirect to SetupTools documentations (pandas-dev#16333)

Author: townie

doc/source/install.rst

@@ -202,7 +202,7 @@ installed), make sure you have `pytest
 Dependencies
 ------------
 
-* `setuptools <http://pythonhosted.org/setuptools>`__
+* `setuptools <https://setuptools.readthedocs.io/en/latest/>`__
 * `NumPy <http://www.numpy.org>`__: 1.7.1 or higher
 * `python-dateutil <http://labix.org/python-dateutil>`__: 1.5 or higher
 * `pytz <http://pytz.sourceforge.net/>`__: Needed for time zone support