Add gradual killer to docs

geraintpalmer · geraintpalmer · commit 00da984c00d8 · 2016-09-19T12:39:08.000+01:00
diff --git a/docs/reference/all_strategies.rst b/docs/reference/all_strategies.rst
@@ -120,3 +120,6 @@ Here are the docstrings of all the strategies in the library.
 .. automodule:: axelrod.strategies.titfortat
    :members:
    :undoc-members:
+.. automodule:: axelrod.strategies.gradualkiller
+   :members:
+   :undoc-members:
