easy_install: update links to documentation

setuptools/command/easy_install.py

@@ -8,7 +8,7 @@ A tool for doing automatic download/extract/build of distutils-based Python
 packages.  For detailed documentation, see the accompanying EasyInstall.txt
 file, or visit the `EasyInstall home page`__.
 
-__ https://pythonhosted.org/setuptools/easy_install.html
+__ https://setuptools.readthedocs.io/en/latest/easy_install.html
 
 """
 
@@ -512,7 +512,7 @@ class easy_install(Command):
         For information on other options, you may wish to consult the
         documentation at:
 
-          https://pythonhosted.org/setuptools/easy_install.html
+          https://setuptools.readthedocs.io/en/latest/easy_install.html
 
         Please make the appropriate changes for your system and try again.
         """).lstrip()
@@ -1256,7 +1256,8 @@ class easy_install(Command):
         * You can set up the installation directory to support ".pth" files by
           using one of the approaches described here:
 
-          https://pythonhosted.org/setuptools/easy_install.html#custom-installation-locations
+          https://setuptools.readthedocs.io/en/latest/easy_install.html#custom-installation-locations
+
 
         Please make the appropriate changes for your system and try again.""").lstrip()