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.

Please review: @tymofij  @cahrens 

@explorerleslie Sandbox is http://studio.auraz.m.sandbox.edx.org/
> After you figure out the LMS test.

These LMS tests where testing content of response for the page where student view of split test module is rendered.
And no vertical names should be rendered there.
Usual workflow is split_tests creates children vertical for itself.
But in these tests, children of split test where created explicitly, and so, split test was not changed their names.

 As now vertical names are Gro