Revert change to travis.yml so it doesn't need to be updated with every version bump
Revert change to travis.yml so it doesn't need to be updated with every version bump

edx-solutions/xblock-drag-and-drop-v2,edx-solutions/xblock-drag-and-drop-v2,edx-solutions/xblock-drag-and-drop-v2,edx-solutions/xblock-drag-and-drop-v2