ajv-errors 1.0.0 incompatible with ajv 6.5.5 cause chrome crash!

schema：

```json
{
"title":"",
"type":"object",
"properties":{
"file_url":{
"type":"object",
"properties":{

}
},
"delay_type":{
"type":"object",
"properties":{
"name":{
"type":"string"
},
"key":{
"type":"string"
}
},
"required":[

],
"keys":[
"delay_type"
]
},
"hold_zwh_time":{
"type":"string"
},
"join_book_url":{
"type":"object",
"properties":{

}
},
"reward_type":{
"type":"object",
"properties":{
"name":{
"type":"string"
},
"key":{
"type":"string"
}
},
"required":[

],
"keys":[
"reward_type"
]
},
"join_oath_date_url":{
"type":"object",
"properties":{

}
},
"join_oath_date":{
"type":"string"
},
"committee_file_url":{
"type":"string"
},
"superior_party_committee_date":{
"type":"string"
},
"other_time":{
"type":"string"
}
},
"required":[
"hold_zwh_time",
"superior_party_committee_date",
"join_oath_date",
"reward_type",
"delay_type",
"other_time"
],
"$id":"ccp_develop_positive_delay",
"errorMessage":{
"type":"object",
"required":{
"other_time":"error tip"
}
}
}
```

model：
{"file_url":{},"join_book_url":{},"join_oath_date_url":{},"reward_type":{"name":"yc","key":"14"},"delay_type":{"name":"other","key":"2","parent":"-1"}}

const ajv = new ajvErrors(Ajv({ allErrors: true, jsonPointers: true, useDefaults: true }));
**const validator = ajv.compile(schema);**
const valid = validator(model);
if (!valid) {
......
}

when execute script like this chrome 70 will block and crash!