Add google.auth.crypt (#6)

diff --git a/docs/reference/google.auth.crypt.rst b/docs/reference/google.auth.crypt.rst
new file mode 100644
index 0000000..7f8c0f8
--- /dev/null
+++ b/docs/reference/google.auth.crypt.rst
@@ -0,0 +1,7 @@
+google.auth.crypt module
+========================
+
+.. automodule:: google.auth.crypt
+    :members:
+    :undoc-members:
+    :show-inheritance: