Merge pull request #1653 from reaperhulk/dsa-interface-move-docs

document that we moved the DSA interfaces
diff --git a/docs/hazmat/primitives/interfaces.rst b/docs/hazmat/primitives/interfaces.rst
index aae891e..bd329b9 100644
--- a/docs/hazmat/primitives/interfaces.rst
+++ b/docs/hazmat/primitives/interfaces.rst
@@ -139,6 +139,12 @@
 
     .. attribute:: name
 
+DSA
+~~~
+
+In 0.8 the DSA key interfaces were moved to the
+:mod:`cryptography.hazmat.primitives.asymmetric.dsa` module.
+
 
 RSA
 ~~~