Napalm-nxos

New Methods:

5 `get_ntp_peers()`
6 `traceroute()`
7 `get_users()`

Changes:
- As per napalm-automation/napalm-base12 - Rename the method `get_ntp_peers` to `get_ntp_stats` and slightly change the output. Check the PR for more details

Driver can now be discovered by napalm-base.

First standalone version. Same features as napalm-0.60.0.