hide-zone-labels: Fix tests & pylint warnings for superfluous imports
hide-zone-labels: Add option to hide the zone labels text (default off)
hide-zone-labels: Remove opacity of popups to always allow to read them
hide-zone-labels: Fix broken test on determining id
hide-zone-labels: Always display the popups on top of dropped items
Merge pull request #18 from edx-solutions/hide-zone-labels

Hide zone labels