Remove d2to1 usage

We don't need d2to1 anymore.

Change-Id: Icbfa11f844600720b344a304439162ba5e49cc9d
diff --git a/setup.py b/setup.py
index 59a0090..c0a24ea 100644
--- a/setup.py
+++ b/setup.py
@@ -17,5 +17,5 @@
 import setuptools
 
 setuptools.setup(
-    setup_requires=['d2to1', 'pbr'],
-    d2to1=True)
+    setup_requires=['pbr'],
+    pbr=True)