Migrate to inspec-gcp resources in tests

[brandonjbjelland]

This PR addresses issue #5 . It:

• moves tests to using inspec-gcp resources.
• upgrades to kitchen-terraform ~> 4.0.0
• removed tests relying on the Command resource as I ran into the following: Resource Command is not supported on platform gcp/google-api-client-v0.19.8.. I think this can be resolved but I didn't spend enough time with it.
• plumbs an environment variable through to the test.

Test output is now the following:

  ✔  instance: Instance database
     ✔  Instance database tag_count should eq 2
     ✔  Instance database status should eq "RUNNING"
     ✔  Instance database machine_type should match "n1-standard-2"
     ✔  Instance database first_network_interface_name should eq "external-nat"
     ✔  Instance database disk_count should eq 2


Profile: Google Cloud Platform Resource Pack (inspec-gcp)
Version: 0.5.0
Target:  gcp://[email protected]

     No tests executed.

Profile Summary: 1 successful control, 0 control failures, 0 controls skipped
Test Summary: 5 successful, 0 failures, 0 skipped

[brandonjbjelland]

Hmm the bottommost failure here indicates.kitchen.yml is lacking the environment variable necessary but the test run seems to actually fail even earlier as we try to read credentials.json. I don't have a lot of visibility into what's going on here since it's wrapped up in the encrypted tarball. Can you look when you have a chance @nictrix ?

ERROR: (gcloud.auth.activate-service-account) Unable to read file [credentials.json]: [Errno 2] No such file or directory: u'credentials.json'
ERROR: (gcloud.config.set) argument VALUE: Must be specified.
Usage: gcloud config set SECTION/PROPERTY VALUE [optional flags]
  optional flags may be  --help | --installation

[nictrix]

This is awesome! Thanks for the updates. I'll check out what's going on with the encrypted tarball/credentials issue. Maybe it's because my free account trial expired. I'll let you know soon.