* refactor nxos_evpn_global * refactor nxos_evpn_vni * refactor nxos_facts * refactor nxos_feature
* fix issues with python3.x * Add integration testa and fix for nxos_evpn_vni * add nxos_evpn_vni to nxos.yaml * fix get_vtp_config() * add new integration tests * fix rollback * add integration test files