[testing] Acceptance tests for rhoas_topic

[juandspy]

Summary

Added some acceptance tests for rhoas_topic. The tests are the same as in #24 and #26:

• TestAccRHOASTopic_Basic: checks that we are able to create a topic and delete it.
• TestAccRHOASTopic_Update: checks that we are able to create topic, change its name and delete it.
  • This one is failing because updating the name makes the resource to be replaced, so the ID is different.
  • This is because the update function is not yet implemented.
  • I left this one skipped waiting for the update feature to come.
• TestAccRHOASTopic_Error: checks that an error is returned if the configuration is wrong. For example, if the name is empty.

I also updated the example as it was outdated.

Testing

Run make testacc. You have to export your OFFLINE_TOKEN variable first.

[jackdelahunt]

👍