Swivel-VPNs without Swivel \o/

General workflow:

1) Run hsrvpn-getsecret to obtain a secret based on the rollout email. Alternatively, obtain it via mitmproxy from the phone app, and run: keyring set hsrvpn-gettokens <username> to set it.

2) Run hsrvpn-gettokens <username> to get 100 tokens based on the secret.

3) Use keyring set openhsr-connect <username> to set your HSR password (unless you use OpenHSR connect already).

4) Run hsrvpn <username> to connect, or hsrvpn-showtoken <username> to show a single token.