fixes manifest to correct path (#222)

lukasheinrich · matthewfeickert · commit 0c62718a830e · 2018-09-01T17:02:54.000Z
diff --git a/MANIFEST.in b/MANIFEST.in
@@ -1,2 +1,2 @@
-validation/data/spec.json
+pyhf/data/spec.json
 
