DOC: fix download link for Anaconda Python

Author: pavoljuhas

README.rst

@@ -66,7 +66,7 @@ functions from the diffpy.srfit.sas module require
 * ``sas`` - module for calculation of P(R) in small-angle scattering
   from the SasView project, http://www.sasview.org
 
-We recommend to use `Anaconda Python <https://www.continuum.io/downloads>`_
+We recommend to use `Anaconda Python <https://www.anaconda.com/download>`_
 as it allows to install all software dependencies together with
 diffpy.srfit.  For other Python distributions it is necessary to
 install the required software separately.  As an example, on Ubuntu