Conditional requirements are listed as required

[AdamGerthel]

Mongoose allow functions that return true or false as value for the required key:

    thisIsAField: {
      type: String,
      required: function(value) {
        return whatever ? true : false
      }
    },

However, express-mongoose-docs lists this as a required field. I propose that field requirements that return a function are listed as "conditional" instead of "true".