Update authorization to 2018-01-01 preview

[jasonodonnell]

I'm updating the authorization packages to 2018-01-01 preview to support roles that use data actions in Azure. The existing authorization package points to 2015-07-01, which does not support them.

Fixes #82.

[calvn]

I see that there are other versions under authorization/mgmt, is there a reason we're going with this one in particular?

There is also a non-preview version for 2018-03-01 and other newer ones.

[austingebauer]

From the diff it appears we originally used 2018-01-01-preview prior to merging #67. That PR switched to using profiles/latest, which appears to point to 2015-07-01. I think that explains why this error is showing up now.

Using 2018-01-01-preview should be fine, but we might want to use something more recent as @calvn suggested. It looks like terraform-provider-azurerm is using 2020-04-01-preview.

[calvn]

Good catch @austingebauer. Let's take a stepwise approach and upgrade back to what it was before, and we can look into bumping that up further afterwards (along with more testing). So upgrading to 2018-01-01-preview sounds good to me.

[austingebauer]

I was able to reproduce the error in #82 and verify that this PR fixes it for both AAD graph and MS graph configurations. Additionally, I fixed the acceptance tests and added coverage for using the Storage Blob Data Owner role which has DataActions/NotDataActions.

Acceptance test output:

➜  vault-plugin-secrets-azure git:(authorization) ✗ go test -v -run TestCredentialInteg_msgraph
=== RUN   TestCredentialInteg_msgraph
=== RUN   TestCredentialInteg_msgraph/service_principals
=== PAUSE TestCredentialInteg_msgraph/service_principals
=== CONT  TestCredentialInteg_msgraph/service_principals
--- PASS: TestCredentialInteg_msgraph (0.00s)
    --- PASS: TestCredentialInteg_msgraph/service_principals (30.37s)
PASS
ok      github.com/hashicorp/vault-plugin-secrets-azure 30.562s

➜  vault-plugin-secrets-azure git:(authorization) ✗ go test -v -run TestCredentialInteg_aad
=== RUN   TestCredentialInteg_aad
=== RUN   TestCredentialInteg_aad/service_principals
=== PAUSE TestCredentialInteg_aad/service_principals
=== RUN   TestCredentialInteg_aad/static_service_principals
=== PAUSE TestCredentialInteg_aad/static_service_principals
=== CONT  TestCredentialInteg_aad/service_principals
=== CONT  TestCredentialInteg_aad/static_service_principals
--- PASS: TestCredentialInteg_aad (0.00s)
    --- PASS: TestCredentialInteg_aad/service_principals (30.98s)
    --- PASS: TestCredentialInteg_aad/static_service_principals (50.91s)
PASS
ok      github.com/hashicorp/vault-plugin-secrets-azure 51.521s