Update poquad.py

poquad.py

@@ -117,7 +117,7 @@ class SquadV2(datasets.GeneratorBasedBuilder):
                         # Features currently used are "context", "question", and "answers".
                         # Others are extracted here for the ease of future expansions.
                         id_ += 1
-                        yield id_, {
+                        yield str(id_), {
                             "title": title,
                             "context": context,
                             "question": question,