Azure - New ResourceGroup model

[bronaghs]

This PR will add a new model for the Azure Resource Group.
A migration for this new model was already merged here: #5026
A separate PR will be made to add a resource_group_id to the Vm model.

[miq-bot]

Checked commit bronaghs@4d789b0 with ruby 1.9.3, rubocop 0.34.2, and haml-lint 0.13.0
3 files checked, 0 offenses detected
Everything looks good. 👍

[chessbyte]

@bronaghs Is a migration needed to create resource_groups table? Or was that done in a previous PR?

[bzwei]

@chessbyte the migration was merged in #5026.
@bronaghs from the migration, why the table has ems_ref and ems_id? I think ems_ref is sufficient. Also why there is no column for location which is included in the return from the API?

[Fryguy]

ems_ref != ems_id . The former is a key from Azure, the latter is the reference to record in the ext_management_systems table.

[bronaghs]

@bzwei - Azure locations will be called Regions in MIQ. Regions in Azure will be mirror Regions in AWS where a Region is its own EMS. Therefore the association between the ResourceGroup and the Region will be represented by the existing ems_id column.