Anton/sync groups and verticals

This fixes https://openedx.atlassian.net/browse/BLD-1095

NB: before merge `ENABLE_GROUP_CONFIGURATIONS` should be set to default value.

First phase reviews: @tymofij  @olmar 
This test should always run, and should override the `FEATURE_GROUP_CONFIGURATIONS` flag to force it to be on. The feature flag should just control whether it displays in production.