* Update Shippable integration test groups.
* Update integration test group aliases.
* Rebalance AWS and Azure tests with extra group.
* Rebalance Windows tests with another group.
This provides a sensu_client module in order to be able to dynamically
configure a Sensu client.
It takes a different approach than the existing Sensu modules such as
sensu_check but is hopefully a much more flexible and simple way of
handling configurations.