genv remote doesn't work on macOS

I ran the following setup on macOS and linux

```
virtualenv .env && source .env/bin/activate
python3 -m pip install genv==1.4.2 setuptools
genv remote -H <remote host> envs
```

On linux it starts connecting to the remote host via SSH, which is what I expect.

On macOS:

```sh
$ genv remote -H <remote host> envs 
genv: ‘remote’: No such file or directory
```