Use correct path for MANIFEST.in (#226)

lukasheinrich · matthewfeickert · commit fbba4b22a43c · 2018-09-01T20:14:25.000Z
diff --git a/MANIFEST.in b/MANIFEST.in
@@ -1,2 +1,2 @@
-pyhf/data/spec.json
+include pyhf/data/spec.json
 
