Use standard meta schema

From ajv's documentation I see there are standard meta schemas that can be used, but how to do that from the CLI?

Using `-m /usr/share/nodejs/ajv/lib/refs/json-schema-draft-04.json` doesn't seem to help at all:
```
meta-schema /usr/share/nodejs/ajv/lib/refs/json-schema-draft-04.json is invalid
error: no schema with key or ref "http://json-schema.org/draft-04/schema#"
```