Unable to provision Aurora engine

[bdelamatre]

It looks like rds_instance has been hardcoded for certain engine types and that Aurora is not an allowed engine type.

Here is a sample of what happens when i specify an engine type of aurora:

Error: Could not set 'present' on ensure: Standalone DB Instances are not supported for the specified engine at /etc/puppetlabs/code/environments/production/modules/provision/manifests/aws/rds/instance/aurora_engine.pp:33
Error: Could not set 'present' on ensure: Standalone DB Instances are not supported for the specified engine at /etc/puppetlabs/code/environments/production/modules/provision/manifests/aws/rds/instance/aurora_engine.pp:33
Wrapped exception:
Standalone DB Instances are not supported for the specified engine
Error: /Provision::Aws::Server::Database::Aurora::Default[staging-database-aurora]/Provision::Aws::Rds::Instance::Aurora_engine[staging-database-aurora]/Rds_instance[staging-database-aurora]/ensure: change from absent to present failed: Could not set 'present' on ensure: Standalone DB Instances are not supported for the specified engine at /etc/puppetlabs/code/environments/production/modules/provision/manifests/aws/rds/instance/aurora_engine.pp:33