* Update Shippable integration test groups.
* Update integration test group aliases.
* Rebalance AWS and Azure tests with extra group.
* Rebalance Windows tests with another group.
(cherry picked from commit 4e489d1be8)
Test that, when a group is created with group_by, variables from the
corresponding group_vars/ file are correctly pulled in, and override
variables specified in group_vars/all.
See ansible/ansible#8664.