Fixes breaking multiple choice choices when publishing. [#66299458]
Fixes breaking multiple choice choices when publishing. [#66299458]

The problem was that the key being used for the external_id should have
been a string, but was an integer.

https://www.pivotaltracker.com/story/show/66299458

concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse