Remove mention of the deploy button from Heroku docs
Commit removed the Heroku instant deploy button but the docs
still mention this as an option, this commit updates the docs to reflect
this change.
@@ -3,7 +3,7 @@ Deployment on Heroku
.. index:: Heroku
-You can either push the 'deploy' button in your generated README.rst or run these commands to deploy the project to Heroku:
+Run these commands to deploy the project to Heroku:
.. code-block:: bash
