Websockets, in which DERP is based, requires a TLS certificate. At the same time,
if we use a certificate it must be valid... otherwise Tailscale wont connect (does not
have an Insecure option). So there is no option to expose insecure here
This series of commit will be adding an embedded DERP server (and STUN) to Headscale,
thus making it completely self-contained and not dependant in other infrastructure.
logs looks like the following
```
2022-03-02T20:43:08Z DBG Expanding alias=app-test
2022-03-02T20:43:08Z DBG Expanding alias=kube-test
2022-03-02T20:43:08Z DBG Expanding alias=test
2022-03-02T20:43:08Z WRN No IPs found with the alias test
2022-03-02T20:43:08Z DBG Expanding alias=prod
2022-03-02T20:43:08Z WRN No IPs found with the alias prod
2022-03-02T20:43:08Z DBG Expanding alias=prod
2022-03-02T20:43:08Z WRN No IPs found with the alias prod
```
- `preauthkey`, `authkey`, `pre` are aliases for `preauthkey` command
- `ls`, `show` are aliases for `list` subcommand
- `c`, `new` are aliases for `create` subcommand
- `revoke`, `exp`, `e` are aliases for `expire` subcommand
- `apikey`, `api` are aliases for `apikeys` command
- `ls`, `show` are aliases for `list` subcommand
- `c`, `new` are aliases for `create` subcommand
- `revoke`, `exp`, `e` are aliases for the `expire` subcommand
- `namespace`, `ns`, `user`, `users` are aliases for `namespaces`
command
- `c`, `new` are aliases for the `create` subcommand
- `delete` is an alias for the `destroy` subcommand
- `mv` is an alias for the `rename` subcommand
- `ls`, `show` are aliases for the `list` subcommand
- `node`, `machine`, `machines` are aliases for `nodes` command
- `ls`, `show` aliases for `list` subcommand
- `logout`, `exp`, `e` are aliases for `expire` subcommand
- `del` is an alias for `delete` subcommand
