Remove unused, broken link

Author: di

source/tutorials/managing-dependencies.rst

@@ -96,7 +96,6 @@ when you share your project with others. You should get output similar to this
     Adding requests to Pipfile's [packages]...
 
 .. _Requests: https://python-requests.org
-.. _pipenv-tox: https://docs.pipenv.org/advanced/#tox-automation-project
 
 
 Using installed packages