Revert "Add error to strategy index."

This reverts commit 2bf4699.

Author: drvinceknight

docs/reference/all_strategies.rst

@@ -80,6 +80,8 @@ Here are the docstrings of all the strategies in the library.
    :members:
 .. automodule:: axelrod.strategies.mindcontrol
    :members:
+.. automodule:: axelrod.strategies.mindreader
+   :members:
 .. automodule:: axelrod.strategies.mutual
    :members:
 .. automodule:: axelrod.strategies.negation