* Add nxos_install_os integration tests
* Update call to check timers
* Update check_ansible_timer method
* Modify network_cli integration tests
* Add timer check for nxos_install_os
* Add comments for clear_persistent_sockets
* Update connection info for tests
* More updates
* Restructure files for provider and non-provider testing
* Update env var name and add check for ISSU switchover