PR stuck on travis-ci check in limbo

This PR updates mockup build to latest in order to fix a regression on plone.app.widgets 1.x branch (unreleased; TinyMCE link modal broken):

The PR checks are stuck on a Travis check, but I do not get the sense that Travis is even aware of this PR yet:

https://travis-ci.org/plone/plone.app.widgets/pull_requests

Anyone have thoughts on what might be stuck?

Sean