Add Database Replica Integration Tests

[gsquire]

This patch adds the remaining database replica integration tests. It also corrects some of the parameters for the replica promote test.

Tested with make test_integration.

Closes #1359

[gsquire]

I do want to call out the fact that I couldn't find the corresponding API for the replica connection command. So there isn't an integration test for that. I searched for 'replica' here. If someone could help point me in the right direction, I can add it in. Thanks!

[andrewsomething]

@gsquire Thanks for this great contribution!

I do want to call out the fact that I couldn't find the corresponding API for the replica connection command.

The replica connection command is a bit of an abstraction. There is a not an endpoint that only returns that information. If you look at the implementation, you'll see that we're calling the GET /v2/databases/$DATABASE_ID/replicas/$REPLICA_NAME endpoint and just surfacing the connection information.

doctl/do/databases.go

Lines 622 to 631 in 0626468

	func (ds *databasesService) GetReplicaConnection(databaseID, replicaID string) (*DatabaseConnection, error) {
	rep, err := ds.GetReplica(databaseID, replicaID)
	if err != nil {
	return nil, err
	}
	return &DatabaseConnection{
	DatabaseConnection: rep.Connection,
	}, nil
	}

[andrewsomething]

👍

[gsquire]

The replica connection command is a bit of an abstraction.

Ah, okay. Thanks for reviewing!