Added GenericSessionMixin because Travis has reported: `load_missing_constant': Unable to autoload constant GenericSessionMixin
Added GenericSessionMixin because Travis has reported: `load_missing_constant': Unable to autoload constant GenericSessionMixin

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic