code: function validateResponse(schema, response, options, done) {
    debug(`validating response for ${schema.endpoint}`);
    // testing status code
    if (schema.status) {
      should(response.status).eql(schema.status);
    }
    return validator.compileAsync(schema).then((validate) => {
      const valid = validate(response.body);
      if (!valid) {
        const errors = validate.errors;
        should(errors).not.be.ok();
        return done(errors);
      }
      if (schema.export) {
        const body = response.body;
        options.vars = options.vars || {};
        for (let dest in schema.export) {
          const propPath = schema.export[dest];
          _.set(options.vars, dest, _.get(body, propPath));
        }
      }
      return done(null, response);
    }).catch(done);
  }
docs: Validate a Http response using schema.
  This handles the actual JSON schema validation.
  
  @private
  @param  {Object} schema - schema used to validate against
  @param  {*} response - http response
  @param  {Object} options - test configurations
  @param  {Function} done - called once validation is completed
  
  @TODO Remove our "extensions" i.e. any custom properties in the
  schema that we have added for the purpose of the elbow utility.