Set up entity_manager

[Skoroglyad]

| Q | A

| ---------------- | -----
| Bug report? | yes
| Feature request? | no
| BC Break report? | yes
| Used Version | 1.0.9

Hello, I have several databases in my app. So, I need to set up specific entity_manager. My config is:

simple_things_entity_audit:
entity_manager: not_default
table_prefix: ''
table_suffix: _audit
revision_field_name: rev
revision_type_field_name: revtype
revision_table_name: revisions
revision_id_field_type: integer
global_ignore_columns:
- created_at
- updated_at
service:
username_callable: acme.username_callable
audited_entities:
- Entity

I get the error:
Unrecognized option "entity_manager" under "simple_things_entity_audit"
Symfony 3.4