The build: https://travis-ci.org/json-schema-org/json-schema-org.github.io/builds/327592609

The reason the build fails after ajv update is that now draft-07 meta-schema is already added to the ajv instance and it is slightly differently defined in ajv than in the spec (the latest change in the spec was to replace empty schemas with true).

I will update the meta-schema in ajv and the issue will go away, but in general the test here needs to be updated to do one of the following:

• replace validations against meta-schema, e.g. ajv test -s schema -d "_includes/person.json" --valid with ajv compile -s _includes/person.json (that will validate against meta-schema by default).
• do not add meta-schema to the instance: ajv test -s schema -d "_includes/person.json" --valid --meta=false --validate-schema=false.

cc @Relequestual