Requirement = function (id, name, isFatal) {
    this.id = id;
    this.name = name;
    this.installed = false;
    this.metadata = {};
    this.isFatal = isFatal || false;
}
Object that represents one of requirements for current platform.
@param {String}  id        The unique identifier for this requirements.
@param {String}  name      The name of requirements. Human-readable field.
@param {Boolean} isFatal   Marks the requirement as fatal. If such requirement will fail
                           next requirements' checks will be skipped.