code: function __removeRequired(obj) {
    while (obj && obj.type === 'array') obj = obj.items;
    delete obj.required;
    if (obj.properties) Object.keys(obj.properties).forEach(p => {
      __removeRequired(obj.properties[p]);
    });
  }
docs: __removeRequired - removes required fields specification
  
  @param  {Object} jsonSchema schema